United States: FTC Highlights Third-Party Report Finding That Companies Are Hiding The Ball On Cross-Device Tracking

Earlier this month, the FTC announced that a third-party study and report on cross-device tracking had been completed by the Office of Technology, Research and Investigation ("OTech"), following up on their presentation on this topic at the FTC's 2015 workshop.  The FTC released its own report on cross-device tracking last week, which will be covered in a subsequent blog post.  OTech's study focused on: 1) what information companies are collecting and may be using to track consumers across devices, and 2) what companies are disclosing about their cross-device tracking in privacy policies or otherwise (the answer is not much!). 

OTech's report underscores the fact that, while increasingly sophisticated data tracking and matching technologies are being developed and used regularly by those in digital advertising, the data subjects (i.e., regular consumers like you and me, who browse the internet across multiple devices) are often kept in the dark about how their data is used and tracked for these purposes.  OTech's study, along with the FTC's 2015 workshop and their own recently released staff report, make clear that this is an area of concern for government regulators, not to mention other self-regulatory bodies in this space –  notably, the Digital Advertising Alliance plans to enforce its 2015 guidance on cross-device tracking for its members beginning in February 2017.  Read on to see what steps companies should be taking to ensure they comply with the latest best practices on cross-device tracking, as per the OTech report.

Taking a Step Back... What is Cross-Device Tracking and Why Do Advertisers Use It?

Cross-device tracking is the practice of tracking and identifying web users across multiple devices.  Or, put another way, cross-device tracking involves the collection, sharing, and matching of data gathered from multiple internet-connected devices (phone, desktop computer, tablet, smartTV, etc.), in order to confirm that those devices are being used by the same person.

This tracking can be used to generate a detailed profile about a particular user's online behavior across multiple devices.  Advertisers, in particular, find this information valuable for market research, retargeting ads to consumers based on their specific preferences and interests, and measuring conversion rates across devices (i.e., measuring those instances where a particular consumer clicks on an ad on one device and then makes a related purchase on another device).

There are two widely-recognized types of cross-device tracking: Deterministic and probabilistic.

  • Deterministic cross-device tracking is when users are asked to log in to websites and apps on every device they use. This allows the operators of those platforms to track their users across devices, linking the devices to a single user account with the same login information. Examples include Facebook, Twitter and Google, which require users to log in no matter what device is used to access those platforms.
  • Probabilistic cross-device tracking involves the collection and use of various data points, such as device type, operating system, IP address, location services, and browsing history, to link multiple devices to a single user, based on predictive algorithms that take into account typical patterns of consumer engagement with multiple devices. Probabilistic tracking can be more concerning from a privacy perspective because, as the FTC noted in connection with its 2015 workshop, it's "generally invisible to consumers, and unlike tracking through cookies, the consumer has no ability to control it."

The OTech Study – What It Found and What It Didn't 

As part of its study, OTech visited the top 20 sites for news, sports, shopping, games and reference (100 sites total) on two different devices to determine what information was being collected and shared across the two devices.

Here's what they found: While there was no definitive evidence that companies observed in the study were engaged in cross-device tracking, they had the capacity to do so.  The visited websites collected and shared with other third-party sites all kinds of information that would allow them to track user behavior across the different devices, as demonstrated in the findings below.

  • 861 third-party domains collected data on both devices, including domains associated with companies who specialize in probabilistic cross-device linking
  • 106 third-party domains shared unique, browser-specific cookie identifiers with 210 other third-party firms including dedicated cross-device tracking companies
  • At least 16 of the 100 sites reviewed shared personally identifiable information — or hashed personally identifiable information – including email addresses or user names — with 60 different third-party domains.

Here's what they didn't find: Despite the figures listed above, many of which suggest cross-device tracking was likely happening, there was barely any disclosure of such tracking in the companies' applicable privacy policies.

The report notes that the privacy policies for the websites it observed "contained little explicit discussion of cross-device tracking specifically, or whether consumers had the ability to turn off cross-device linkage."  Of the 100 websites assessed, OTech found that just three provided any information about enabling third-party cross-device tracking.

The Takeaways

As cross-device tracking technologies become more sophisticated, advertisers will rely on such technologies with increasing frequency to create and serve more effective and innovative advertising.  The FTC's workshop and this third-party study demonstrate, however, that regulators consider cross-device tracking to be a potential minefield for privacy concerns, both because the technology is becoming more complicated and because consumers have limited visibility into how it works and when it's even being used.  Those in the digital advertising space should take heed of this report and the DAA's guidance by applying the core privacy principles of transparency, notice, and choice to these practices.

In particular, advertisers and related parties engaged in cross-device tracking should:

Be Transparent and Provide Notice 

  • Clearly disclose in privacy policies whether they (or any third parties with whom they share information) are engaged in cross-device tracking and how such "device-aggregated" data is being used;
  • Consider updating agreements with clients and service providers to ensure they have disclosures on cross-device tracking in their privacy policies

Give Users Choices and Honor Their Preferences

  • Tell users in privacy policies (or other notifications, if applicable) how they can opt-out of device linkage, including by providing links to any third-party sites where consumers can indicate these preferences. For users, this could involve the laborious process of opting out on each of their devices and browsers and checking regularly to ensure those preferences are maintained.
  • Honor consumer opt-outs across all devices associated with that user. This means that if a user opts out of cross-device tracking on one device, data collected from that device should not be used to serve them ads (or for any other purpose) on any of their other devices, or shared with unaffiliated third parties.


This post first appeared in Frankfurt Kurnit's Focus on the Data blog (www.focusonthedata.com). It provides general coverage of its subject area. We provide it with the understanding that Frankfurt Kurnit Klein & Selz is not engaged herein in rendering legal advice, and shall not be liable for any damages resulting from any error, inaccuracy, or omission. Our attorneys practice law only in jurisdictions in which they are properly authorized to do so. We do not seek to represent clients in other jurisdictions.

To print this article, all you need is to be registered on Mondaq.com.

Click to Login as an existing user or Register so you can print this article.

Similar Articles
Relevancy Powered by MondaqAI
Frankfurt Kurnit Klein & Selz
Sheppard Mullin Richter & Hampton
In association with
Related Topics
Similar Articles
Relevancy Powered by MondaqAI
Frankfurt Kurnit Klein & Selz
Sheppard Mullin Richter & Hampton
Related Articles
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Registration (you must scroll down to set your data preferences)

Mondaq Ltd requires you to register and provide information that personally identifies you, including your content preferences, for three primary purposes (full details of Mondaq’s use of your personal data can be found in our Privacy and Cookies Notice):

  • To allow you to personalize the Mondaq websites you are visiting to show content ("Content") relevant to your interests.
  • To enable features such as password reminder, news alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our content providers ("Contributors") who contribute Content for free for your use.

Mondaq hopes that our registered users will support us in maintaining our free to view business model by consenting to our use of your personal data as described below.

Mondaq has a "free to view" business model. Our services are paid for by Contributors in exchange for Mondaq providing them with access to information about who accesses their content. Once personal data is transferred to our Contributors they become a data controller of this personal data. They use it to measure the response that their articles are receiving, as a form of market research. They may also use it to provide Mondaq users with information about their products and services.

Details of each Contributor to which your personal data will be transferred is clearly stated within the Content that you access. For full details of how this Contributor will use your personal data, you should review the Contributor’s own Privacy Notice.

Please indicate your preference below:

Yes, I am happy to support Mondaq in maintaining its free to view business model by agreeing to allow Mondaq to share my personal data with Contributors whose Content I access
No, I do not want Mondaq to share my personal data with Contributors

Also please let us know whether you are happy to receive communications promoting products and services offered by Mondaq:

Yes, I am happy to received promotional communications from Mondaq
No, please do not send me promotional communications from Mondaq
Terms & Conditions

Mondaq.com (the Website) is owned and managed by Mondaq Ltd (Mondaq). Mondaq grants you a non-exclusive, revocable licence to access the Website and associated services, such as the Mondaq News Alerts (Services), subject to and in consideration of your compliance with the following terms and conditions of use (Terms). Your use of the Website and/or Services constitutes your agreement to the Terms. Mondaq may terminate your use of the Website and Services if you are in breach of these Terms or if Mondaq decides to terminate the licence granted hereunder for any reason whatsoever.

Use of www.mondaq.com

To Use Mondaq.com you must be: eighteen (18) years old or over; legally capable of entering into binding contracts; and not in any way prohibited by the applicable law to enter into these Terms in the jurisdiction which you are currently located.

You may use the Website as an unregistered user, however, you are required to register as a user if you wish to read the full text of the Content or to receive the Services.

You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these Terms or with the prior written consent of Mondaq. You may not use electronic or other means to extract details or information from the Content. Nor shall you extract information about users or Contributors in order to offer them any services or products.

In your use of the Website and/or Services you shall: comply with all applicable laws, regulations, directives and legislations which apply to your Use of the Website and/or Services in whatever country you are physically located including without limitation any and all consumer law, export control laws and regulations; provide to us true, correct and accurate information and promptly inform us in the event that any information that you have provided to us changes or becomes inaccurate; notify Mondaq immediately of any circumstances where you have reason to believe that any Intellectual Property Rights or any other rights of any third party may have been infringed; co-operate with reasonable security or other checks or requests for information made by Mondaq from time to time; and at all times be fully liable for the breach of any of these Terms by a third party using your login details to access the Website and/or Services

however, you shall not: do anything likely to impair, interfere with or damage or cause harm or distress to any persons, or the network; do anything that will infringe any Intellectual Property Rights or other rights of Mondaq or any third party; or use the Website, Services and/or Content otherwise than in accordance with these Terms; use any trade marks or service marks of Mondaq or the Contributors, or do anything which may be seen to take unfair advantage of the reputation and goodwill of Mondaq or the Contributors, or the Website, Services and/or Content.

Mondaq reserves the right, in its sole discretion, to take any action that it deems necessary and appropriate in the event it considers that there is a breach or threatened breach of the Terms.

Mondaq’s Rights and Obligations

Unless otherwise expressly set out to the contrary, nothing in these Terms shall serve to transfer from Mondaq to you, any Intellectual Property Rights owned by and/or licensed to Mondaq and all rights, title and interest in and to such Intellectual Property Rights will remain exclusively with Mondaq and/or its licensors.

Mondaq shall use its reasonable endeavours to make the Website and Services available to you at all times, but we cannot guarantee an uninterrupted and fault free service.

Mondaq reserves the right to make changes to the services and/or the Website or part thereof, from time to time, and we may add, remove, modify and/or vary any elements of features and functionalities of the Website or the services.

Mondaq also reserves the right from time to time to monitor your Use of the Website and/or services.


The Content is general information only. It is not intended to constitute legal advice or seek to be the complete and comprehensive statement of the law, nor is it intended to address your specific requirements or provide advice on which reliance should be placed. Mondaq and/or its Contributors and other suppliers make no representations about the suitability of the information contained in the Content for any purpose. All Content provided "as is" without warranty of any kind. Mondaq and/or its Contributors and other suppliers hereby exclude and disclaim all representations, warranties or guarantees with regard to the Content, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. To the maximum extent permitted by law, Mondaq expressly excludes all representations, warranties, obligations, and liabilities arising out of or in connection with all Content. In no event shall Mondaq and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use of the Content or performance of Mondaq’s Services.


Mondaq may alter or amend these Terms by amending them on the Website. By continuing to Use the Services and/or the Website after such amendment, you will be deemed to have accepted any amendment to these Terms.

These Terms shall be governed by and construed in accordance with the laws of England and Wales and you irrevocably submit to the exclusive jurisdiction of the courts of England and Wales to settle any dispute which may arise out of or in connection with these Terms. If you live outside the United Kingdom, English law shall apply only to the extent that English law shall not deprive you of any legal protection accorded in accordance with the law of the place where you are habitually resident ("Local Law"). In the event English law deprives you of any legal protection which is accorded to you under Local Law, then these terms shall be governed by Local Law and any dispute or claim arising out of or in connection with these Terms shall be subject to the non-exclusive jurisdiction of the courts where you are habitually resident.

You may print and keep a copy of these Terms, which form the entire agreement between you and Mondaq and supersede any other communications or advertising in respect of the Service and/or the Website.

No delay in exercising or non-exercise by you and/or Mondaq of any of its rights under or in connection with these Terms shall operate as a waiver or release of each of your or Mondaq’s right. Rather, any such waiver or release must be specifically granted in writing signed by the party granting it.

If any part of these Terms is held unenforceable, that part shall be enforced to the maximum extent permissible so as to give effect to the intent of the parties, and the Terms shall continue in full force and effect.

Mondaq shall not incur any liability to you on account of any loss or damage resulting from any delay or failure to perform all or any part of these Terms if such delay or failure is caused, in whole or in part, by events, occurrences, or causes beyond the control of Mondaq. Such events, occurrences or causes will include, without limitation, acts of God, strikes, lockouts, server and network failure, riots, acts of war, earthquakes, fire and explosions.

By clicking Register you state you have read and agree to our Terms and Conditions