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Originally published by Privacy Foundation
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Chronology of Written Reports
- Original report (below) posted March 26, 2001
-
Letter
from Reps. Dingell, Towns, and Markey requesting Federal Trade
Commission (FTC) investigation, March 28, 2001
-
TiVo's white
paper to the FTC describing their privacy practices, May 3, 2001
-
FTC response to Reps. Dingell, Towns, and Markey, May 11, 2001
Rough summary: TiVo's later privacy policies
(including those available in 2001) no longer claim that "all of your
personal viewing information remains on your [TiVo] in your home".
This is important, because the report below shows how that statement was
(and perhaps even still is) not true. But in no longer making that
claim and instead promising not to misuse any personal viewing information
that they might encounter -- as well as intentionally if not perfectly separating the viewing data from subscriber identity
-- TiVo is doing just fine. In light of these changes, it seems appropriate
that the FTC to declined to undertake a full investigation in 2001. By
the way, I love my TiVo.
David Martin
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TiVo's Data Collection and Privacy
Practices |
By
David
Martin Assistant Professor of Computer Science,
University of Denver
March 26, 2001
Introduction Vendor
Response TiVo
Background and Business Model Information
Gathering by the TiVo Device The
Diagnostic Log File The
Viewing Information File Viewing
Information: Anonymous or Not? Technical
Details: Transferring the Information TiVo's
Privacy Disclosures Legal
Concerns Recommendations
to TiVo Inc. Recommendations
to TiVo Subscribers Listening
to TiVo's Transmissions Acknowledgments Related
Links
Introduction
The TiVo personal
television product gives home viewers the ability to pause
live television, record TV shows by name rather than time and
channel, and generally allows users to "time-shift" TV
broadcasts into their own schedule. In exchange, TiVo collects
both a subscription fee and information about the shows that
home viewers record and watch. The Privacy Foundation and
University of Denver Privacy Center have recently completed a
4-month independent investigation of the TiVo
device.
According to our findings, TiVo:
gathers enough information to track individual
users' home viewing habits while apparently promising not to
do so;
could identify the personal viewing habits of
subscribers at will;
has a much
more explicit privacy policy disclosure on its Web site than
in the printed material that accompanies the purchase of the
product.
The TiVo unit we investigated was sold as a
Philips HDR312 at a local Circuit City store.
Vendor Response
A draft version of
this privacy advisory was provided by the Privacy Foundation
to TiVo on March 14, 2001. Senior officers of the company
responded in a phone call on March 19, 2001 with the following
points:
TiVo turns
off all logging at the incoming FTP servers to prevent the
correlation of the anonymous viewing files with the diagnostic
files that contain customer ID numbers. TiVo takes a number of
other steps to prevent anonymous viewing files from being
traced back to TiVo subscribers.
TiVo claims
that it is only interested in compiling customer data to
assess aggregate viewing behavior, and has no plans to
identify the viewing habits of individuals, nor to use such
data for direct marketing purposes.
The
server-side practices of TiVo are beyond the scope of the
advisory. TiVo also notes that data about customers is kept in
secure servers that can only be accessed by authorized TiVo
employees.
Version 2.0
of the TiVo software will encrypt files that contain personal
information, as described in the latest Privacy
Promise.
The latest
version of the TiVo Privacy Promise, dated September 2000,
addresses many of the issues which the Privacy Foundation
advisory brings up. This Privacy Promise is available online
at http://www.tivo.com/support/service_privacy_pvr.asp.
TiVo
acknowledges that its privacy practices and disclosures may
not be up-to-date in manuals sold with TiVo units, but the
company notes that it attempts to alert all customers about
the availability of the new Privacy Promise via email and
messages on the TiVo service.
TiVo Background and Business
Model
Launched in 1999, the TiVo service allows
viewers to easily record favorite TV programs, or types of
programs, for later viewing through a set-top box that can
record up to 30 hours or more of programming. The TiVo box can
cost several hundred dollars at retail, plus a monthly
subscription fee of $9.95; a yearly fee of $99.95; or a
lifetime subscription fee of $199.
TiVo Inc., the
publicly-traded parent company based in San Jose, Calif., has
alliances with major media and technology companies, including
its equipment vendors, Philips and Sony; General Electric/NBC;
DirecTV; and a $200 million investment from AOL Time Warner.
In August of 2000, Nielsen Media Research and TiVo announced a
strategic agreement to enable opt-in audience measurement
through the TiVo service.
As of Jan. 31, 2000, TiVo
Inc. reported an installed subscriber base of 154,000. The net
loss for the calendar year 2000 was $206.4 million, on
revenues of $3.6 million.
Aggressive estimates by
industry analysts claim that the market for "personal video
recorders" from TiVo and other vendors could reach
five-to-seven million units by year-end 2002. ReplayTV, a
primary competitor to TiVo, was acquired in February by
Sonicblue in a $123 million stock deal. In January, Microsoft
announced the launch of its UltimateTV service, which
integrates DirecTV programming, digital video recording, live
TV controls, interactive television and Internet
access.
Among the future business opportunities for
TiVo is providing targeted advertising to viewers, according
to the company's year-end 2000 report: "This is accomplished
by a software program utilizing data stored on the personal
video recorder. Individual viewing preferences will not be
released to advertisers or other third parties."
TiVo
is aware of privacy concerns. In the risks section of its 2000
Annual Report, TiVo writes: "Consumers may be concerned about
the use of personal information gathered by the TiVo Service
and personal video recorder. Under our current policy, we do
not access this data or release it to third parties. Privacy
concerns, however, could create uncertainty in the marketplace
for personal television and our products and services. Changes
in the privacy policy could reduce demand for the TiVo
Service, increase the cost of doing business as a result of
litigation costs or increased service delivery costs, or
otherwise harm our reputation and business."
TiVo has
received generally favorable press coverage, including a March
18 segment on "60 Minutes." An Aug. 13, 2000, New York Times
Magazine story on TiVo made this observation about the promise
of its technology: "While the viewer watched the television,
the box would watch the viewer. It would record the owner's
viewing habits in a way that TV viewing habits had never been
recorded."
Information Gathering by the TiVo
Device
During TiVo installation, the installer
connects the TiVo unit to a cable TV feed or other video
source, a television, and the home phone line. The home user
then controls the television exclusively through the TiVo
remote control.
During an automatic daily phone call,
the TiVo device gets a new copy of the most recent TV schedule
from computers at TiVo headquarters. But during the same phone
call, the TiVo device also transmits information to TiVo
headquarters. At least two different types of information are
transmitted: a diagnostic log file and a viewing information
file.

The Diagnostic Log File
The
diagnostic log file (a "syslog") contains various debugging
and system status reports, such as memory consumption, user
interface response time, modem communication records,
enclosure temperature, and enclosure fan speed. Here are some
sample lines from the diagnostic log:
- Jan 13 06:29:44 (none)
fancontrol[54]: The current board temperature is 41
Jan
13 06:29:44 (none) fancontrol[54]: Setting the fan speed to
9 Jan 13 06:39:44 (none) fancontrol[54]: The current
board temperature is 37 Jan 13 06:39:44 (none)
fancontrol[54]: Setting the fan speed to 0 Jan 13
17:42:10 (none) LogTime[94]: WatchTV: change the channel:
0.015 sec Jan 13 17:42:55 (none) LogTime[94]: Lineup:
update the OSD: 0.949 sec Jan 13 17:42:56 (none)
LogTime[94]: Lineup: arrow up/down: 0.011 sec Jan 13
17:42:57 (none) LogTime[94]: Lineup: arrow up/down: 0.009
sec Even though the diagnostic log does
not indicate which shows are being watched by the home viewer,
entries like the last lines above do indicate that someone was
manipulating the TiVo remote control at 5:42 pm on January
13.
The diagnostic log contains an enormous amount of
information about the TiVo�s device�s internal processes. On
one day, for instance, we observed almost 100 pages of
information being deposited in the diagnostic log. We are not
aware of any other consumer device that routinely transmits so
much operational information to corporate
headquarters.
A sample diagnostic log file is available
in the Related Links section of this advisory.
The Viewing Information File
The
viewing information records transmitted to TiVo headquarters
look like this in raw form:
- 980389559|WatchTV|recorded|KDVR|3134603|980127000
The
two numbers beginning with 980 are timestamps that count the
number of seconds that have elapsed since midnight on January
1, 1970, and the number 3134603 identifies a specific
television program. This record can be interpreted
as:
"On Wednesday, January 24 2001 at 7:26pm, the home
viewer began watching an episode of King of the Hill that was
originally recorded on Sunday, January 21 2001 at 6:30pm on
the KDVR station."
We also observed TiVo transmitting
viewing records such as these:
- 980389520|WatchTV|live|IFC|27666|980384400
980389546|MWEvent|tyTivo 980389550|MWEvent|tySurfDown 980389565|MWEvent|tyVolumeUp The
first line above reveals the home user tuning in the movie "My
Own Private Idaho" on the Independent Film Channel (IFC), and
the three lines below it correspond directly to pushing
buttons on the TiVo remote control.
Viewing Information: Anonymous or
Not?
When the viewing information file is
transmitted to TiVo headquarters, it is deposited into a
common area for gathering subscriber data. The TiVo unit does
not explicitly attach the viewer's identification number to
the file in this step, and this is partially why TiVo
considers the information "anonymous".
TiVo describes
this practice as a "very sophisticated mechanism" to ensure
that the subscriber information cannot be linked with the
"anonymous" viewing information. However, the viewing
information file is nonetheless transmitted during a session
identified by the home viewer's TiVo serial number. In fact,
this serial number is transmitted multiple times during the
single phone call. TiVo receives all of the information
necessary to attribute the viewing information to a particular
subscriber during this phone call but gives no indication of
this fact in any of its documentation. Therefore, the home
viewing information can only be truly anonymous when TiVo
headquarters intentionally treats it as such. TiVo�s current
"anonymization" procedure does not change that fact.
Technical Details: Transferring the
Information
TiVo�s actual file transfer mechanism
works as follows. During the daily phone call, TiVo
headquarters chooses a name for the receiver�s viewing
information file and a name for the diagnostic log and
transmits both to the TiVo unit. If one of these file names
includes the word "RANDOMIZE", then the TiVo unit replaces
that word with a large randomly chosen number. This allows
TiVo headquarters to decide whether a file�s name will include
identifying information or not. The TiVo unit then begins
transferring the two data files to the TiVo headquarters
computer, saving them under the chosen names.
Under
normal operation, TiVo headquarters includes the word
"RANDOMIZE" in the viewing information file name and the TiVo
unit serial number in the diagnostic log file name. This means
that the viewing information file name will not immediately
identify a subscriber, but the diagnostic log file name
will.
For example, we first saw TiVo headquarters
choose and transmit the names
- /TivoData/bprv/20010124/000000.RANDOMIZE.80208.bz2
/TivoData/bpub/20010124/184023.00840336485942.log.bz2 and
then we observed our TiVo unit depositing files onto the TiVo
server computer with the names
- /TivoData/bprv/20010124/000000.C41CF33D1DC7F401.80208.gz
/TivoData/bpub/20010124/184023.00840336485942.log.gz The
first file, which contains the viewing information, is sent to
the "private" (bprv) directory and stored under a name that
only identifies the subscriber�s zip code. But the diagnostic
log file goes to the "public" (bpub) directory, and is stored
under a name that contains a TiVo unit's serial number � in
this case 00840336485942. Both files clearly show the date of
the transfer, 2001 01/24.
Since both files are
transferred to the same computer during the same phone call,
this computer can easily reattach the subscriber ID to the
viewing information file. In addition, it is standard computer
security practice to keep a record of every FTP file that is
transferred. These FTP records normally indicate both the name
of the file transferred and the IP address of the computer (or
TiVo unit) that initiated the transfer. Just by consulting
this log file � even months or years after the fact � TiVo
could easily reconstruct the subscriber ID that deposited a
viewing information file. (We have no direct way to tell if
FTP logging is on or off, but TiVo representatives indicated
that FTP logging is disabled.)
TiVo's Privacy Disclosures
We
found three privacy statements that concern our Philips
TVR312. Two of them are in the manual that accompanied the
Philips TiVo unit, and the third is on the TiVo Web
site.
First disclosure. The first mention of
privacy appears about halfway through the manual on page 56 as
an answer to a frequently asked question:
- Will the TiVo Service collect
information about my viewing habits?
There has been quite
a bit of misplaced hype about TiVo collecting viewing
information. At TiVo, we absolutely respect and guard your
right to privacy. We have a privacy policy that maintains
complete viewer confidentiality. Unlike the Internet, all of
your personal viewing information remains on your PTV
receiver in your home. TiVo has created a very sophisticated
system with both protection and customization for our
viewers in mind. It is TiVo's promise to you that you will
always maintain control over your own personal information.
For more information see the TiVo Privacy Promise, pages
133-134.
This first disclosure is the
most accessible to users because it occurs in the main text of
the user manual. Users reading it are likely to understand
that TiVo is offended at the notion ("misplaced hype") that
TiVo might even be suspected of "collecting viewing
information." Then stating that "all of your personal viewing
information remains on your [TiVo] receiver in your home",
TiVo sends a signal that any such suspicion is totally
unfounded because viewing information never leaves the TiVo
device.
It is important to observe that TiVo does not
include their unusual definition of "personal viewing
information" at this point. Therefore, a reader might
rationally conclude at this point that absolutely no
information about TV viewing ever leaves the TiVo device under
the reasonable assumption that all information about the shows
viewed at home is "personal" � i.e., due to personal action.
For these subscribers, the first disclosure has the effect of
limiting interest in the second and third
disclosures.
Second disclosure. This disclosure
begins with a preamble on page 132:
- Privacy
Your Philips PTV
Receiver is powered by the TiVo Service. Philips and TiVo
are committed to protecting the privacy of your personal
information. TiVo has established a strict privacy policy
for the TiVo Service, which is published on TiVo�s website,
www.tivo.com. We have reprinted it here as well for your
convenience.
The privacy disclosure
following this statement in the manual may be a reprinting of
a policy that was posted on TiVo�s Web site at one time, but
when we purchased the TiVo unit in late 2000, the TiVo manual
policy and the Web site policy were no longer the same. The
Web site privacy policy was already much more detailed and
explicit than anything printed in the TiVo manual.
TiVo
presents the main text of this second privacy disclosure on
page 133:
- TiVo's Privacy Promise to
You
Please read this policy document carefully
[...] 1. Personal Viewing Information. Your Personal
Television (PTV) Receiver keeps track of viewing information
� the programs you ask it to record and any time buttons on
the PTV Remote Control, such as "Thumbs Up" or "Thumbs
Down," are pressed. Your PTV Receiver uses it to tune,
schedule, record, and recommend programs for you. Personal
viewing information which identifies you or your household's
TV viewing practices belong to you, and no one outside your
home, not even the TiVo staff or any of TiVo's computer
systems, will have access to it without your prior
consent. 2. Anonymous Viewing Information. Anonymous
viewing information is viewing information that does not
identify you as an individual or your household. This means
it is not linked to you or your household in any way. We may
use anonymous viewing information to benefit TiVo and
strengthen our efforts to encourage the television industry
to better serve the interests of TiVo subscribers. If you
don't want anonymous viewing information used in any way,
simply tell us by calling our toll-free telephone number and
it will not be. [...] Please note: Our privacy policy
may change over time. In addition to posting any changes on
our web site, www.tivo.com, we will provide or send a notice
to each TiVo customer before any changes are implemented.
You have our commitment that, regardless of any changes that
might be made in the future, you will remain in complete
control of your personal viewing information. Use of your
PTV Receiver or TiVo Service will signify your acceptance of
these privacy policies. The statement in
point 1 that "[none] of TiVo�s computer systems will have
access to [your personal information] without your prior
consent" appears to be incorrect. As previously described, the
TiVo headquarters computer receives viewing information and
the subscriber identity during the same phone
call.
TiVo introduces "personal" and "anonymous"
viewing information for the first time in this second
disclosure. Only now can subscribers who also read the first
disclosure suspect that all of its 5 sentences of reassurance
must have concerned only "personal" information, since
apparently an opt-out action is required to limit the use of
"anonymous" information, while the first disclosure did not
mention any required user action.
The text in point 2
above is the complete description of "anonymous" viewing
information in the TiVo manual, and it offers an extremely
vague statement of the intended use of the information. In
particular, it does not disclose that this "anonymous"
information is transmitted routinely to TiVo headquarters. The
only possible indication that "anonymous" information might be
transmitted comes from the juxtaposition between point 1
declaring that "personal" information is not transmitted, and
the lack of a similar statement in point 2.
The phrase
"Personal viewing information which identifies you or your
household's TV viewing practices belong to you" is TiVo�s
clearest attempt to define "personal viewing information" in
the TiVo manual. But equating "personal information" with the
industry-standard term "personally identifiable information"
is incorrect and likely to mislead readers. According to
standard dictionaries, "personal" means "pertaining to or
concerning a particular person", not "explicitly labeled with
a subscriber identity".
Neither the first nor the
second disclosure even mentions the existence of the
diagnostic log.
Third disclosure. The second
disclosure refers its users to the TiVo Web site for the third
privacy statement. Forcing the user to hunt through a Web site
for a more current statement is an unfair practice: TiVo is
not itself a Web browser, nor does it otherwise require the
use of the Web. Users without Web access have no practical
means to obtain this third disclosure.
Those who do
have Web access must start at www.tivo.com and pick the
correct choice from the more than ten links visible on this
page. Only some customers will choose "Customer Support" in
order to continue their search for the third disclosure,
because no instructions are given anywhere that this is the
correct way to proceed. Users can then select "Privacy
Promise" and then "Personal Video Recorder With TiVo Service
Privacy Promise" in order to begin viewing the third
statement. The third statement itself is split over four Web
pages. Only determined customers will have the patience to
click through these seven pages total in order to read the
third disclosure.
The third disclosure is more
extensive and much longer than the first two. It is consistent
with the paper-based policy where they overlap, but is more
carefully written and volunteers much more information about
TiVo's privacy and business practices. For example, the
Web-based policy states clearly that the "anonymous" viewing
log and the diagnostic log are indeed transmitted from the
TiVo device to TiVo headquarters.
Although the third
disclosure includes more information, it also introduces some
new problems. Section 9.4 reads in part:
- This Privacy Promise constitutes the
entire agreement, and replaces and supersedes all prior
agreements, between you and TiVo concerning the subject
matter discussed in this Privacy Promise. Use of your
Recorder with TiVo will signify your acceptance of this
Privacy Promise.
It is hard to believe
that users without Web access truly signify their acceptance
of this disclosure, which they have not read, simply by using
the device under the assumption that the privacy policy
included in its manual was complete. In addition,
Section 5.1 claims that the diagnostic log
contains "no Contact Information whatsoever", even though we
observed that the diagnostic log is deposited under a name
that includes the TiVo device's serial number � and this links
directly to a customer's account.
Even the
third disclosure does not state that the diagnostic log
indicates the times when the TiVo remote control was in
use.
Section 8 states that TiVo uses
"industry-standard methods such as encryption to secure the
communication of Subscriber Information from your Receiver to
TiVo". However, we observed no encryption protecting the
viewing information or the diagnostic log.
Section 9.1 declares that modifications to the
stated privacy policy will be announced and described via the
TiVo messaging system � i.e., TiVo subscribers will be alerted
by their television that a new privacy policy has been issued.
However, we never received notice of the Web-based third
disclosure after installing our TiVo unit. Since this third
privacy statement is substantially different than the first
two, we should have been alerted to its presence.
Not
even the third disclosure mentions that TiVo modifies its
receivers� software from time to time. In other words, TiVo
Inc. changes the behavior of the purchased device without
obtaining the consent of the purchaser. This has security,
reliability, ownership, and privacy implications.
In
summary, the first disclosure appears to say that no viewing
information is transmitted and directs users to the second
disclosure. The second disclosure indicates that anonymous
viewing information exists, but says nothing useful how it is
used in practice, and directs users to the third disclosure if
they have Web access. The third disclosure is explicit and
well written but introduces some new errors.
Legal Concerns
Given these
conflicts between the stated privacy policies and their actual
practices, as well as potential practices, TiVo would be wise
to consider its potential legal exposure for breach of
contract, deceptive trade practices, invasion of privacy, and
other legal theories, according to an analysis by Privacy
Foundation legal experts. In addition, the information in the
diagnostic log named with a TiVo serial number may be subject
to disclosure in response to a subpoena issued by a prosecutor
in a criminal proceeding or by a litigant in a civil
proceeding.
Recommendations to TiVo Inc.
TiVo
should resolve the discrepancies between its stated policies
and its actual practices as documented in this advisory. Until
it adopts a long-term solution, TiVo can and should
immediately stop collecting diagnostic logs and viewing
information from all of its subscribers.
If TiVo wants
to collect viewing information, it should ask for subscriber
permission. New TiVo owners must already go through a lengthy
"guided setup" that asks many questions about their audio,
video, and telephone equipment in order to properly configure
the TiVo unit. TiVo could easily ask for user permission to
gather viewing information during this phase. The current
practice of assuming that the subscriber, simply by turning on
the TiVo box, has consented to the Web-based privacy policy �
while TiVo complains of "misplaced hype" � is confusing, at
best.
Users should be able to change their privacy
preferences at any time through the TiVo user interface. Some
subscribers may, in fact, want their viewing information
captured in order to communicate the popularity of a program �
or to participate in an opt-in research study with Nielsen, a
TiVo partner.
TiVo should
tell customers what happens in straightforward language. "At
night, we get a list of the shows you recorded and watched" is
much clearer than "We may use anonymous viewing information to
benefit TiVo and strengthen our efforts to encourage the
television industry to better serve the interests of TiVo
subscribers."
TiVo should
not claim that personal viewing information "remains on your
receiver," because this suggests that the viewing information
is never transmitted elsewhere. In fact, all of the
constituent pieces of the personal viewing information are
transmitted to TiVo�s computers.
TiVo should
disclose that their customer-identified diagnostic log can
indicate when the TiVo remote control was in use.
TiVo
should obtain subscriber consent before updating the software
in their subscribers� TiVo units.
Recommendations to TiVo
Subscribers
TiVo permits its subscribers to disable
the collection of viewing information and diagnostic logs by
calling TiVo toll-free at 1-877-367-8486
(1-877-FOR-TIVO).
Listening to TiVo's
Transmissions
In order to prepare this report, we
simply monitored calls made on our own phone line. We never
even opened the TiVo case.
Roughly speaking, we
constructed a modem sniffing station consisting of two phone
jacks connected to modems on a standard laptop computer. We
then connected the TiVo device�s telephone jack to the
station�s incoming telephone jack, and we connected the
station�s outgoing jack to the real phone system. When the
TiVo device made a telephone call, our system passed through
the contents of the phone call undisturbed while saving a copy
of everything transmitted over the line. We then analyzed the
captured data, which led to the findings in this
advisory.
We plan to describe our modem sniffing
platform more fully in a future report.

Acknowledgments
Julie Rech, Phil
Gordon, Stephen Keating, Richard M. Smith, and Prof. John Soma
contributed to this report. Matt Blaze of AT&T Research
originally suggested the modem sniffing approach.
Related Links
A Sample TiVo Diagnostic Log File We
captured this diagnostic log on January 13, 2000. It contains
almost 100 pages of text (6543 lines, 455KB), all concerning
the TiVo unit's operation on that day. We have used asterisks
(*****) to replace some possibly sensitive information in the
log.
The Official TiVo Web Site
The TiVo Area Within the AVS Forum
The TiVo Hacking Web Site
Boom Box, The New York Times
Magazine, 8/13/00
The Spy Interactive Web Site
New Bill Targets TV Privacy, Wired
News, 2/23/00
Is Your TV Set Watching You?, Richard's
Tipsheet, 1/16/01
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