Report scrutinizes online tracking practices

Aug. 4, 2011, 2:01 a.m.

Two recent reports from Stanford Security Lab (SSL) researchers have fueled an ongoing debate over privacy issues in the largely self-regulated online advertising industry.

The findings, released June 12 and June 19, respectively stated that some online advertising companies contradict their privacy policies after consumers choose to “opt-out” of tracking and that Epic Marketplace, another online advertising firm, was “history stealing” from users. All the agencies involved participate in the Network Advertising Initiative, a cooperative of online advertisers that has self-regulated the industry since 1999.

Report scrutinizes online tracking practices
(SERENITY NGUYEN/The Stanford Daily)

“[One] reason I think self-regulation is falling apart is that we identified eight companies with privacy policies that might be interpreted to be in conflict with their current business practices,” said Jonathan Mayer, a second-year graduate student in computer science and law, who is on the SSL research team and authored the two reports. “It’s important to note that these are privacy representations that the companies chose to make themselves–beyond what NAI requires.”

Epic Marketplace did not respond to requests for comment but decried the bias of the term “history stealing” in a blog post, writing, “this type of data collection occurs in virtually every web transaction.”

According to Mayer’s report, Epic Marketplace uses a number of quick and complex algorithms that determine whether users have visited specific sites, like Groupon and Starbucks. It even searches for specific history, like viewing pages about pregnancy and fertility at the Mayo Clinic or bad credit and debt relief at the Federal Trade Commission (FTC).

NIA, which also did not respond to requests for comment, requires its members to stop delivering ads targeted to the consumer based on his browsing patterns when he opts out; it does not require them to cease “third-party tracking,” which involves collecting information like the quantitative effectiveness of the ad or whether agencies delivered the number of ads their clients agreed upon. There is no clear consensus between ad agencies, privacy watchdogs or regulators about what tracking means or what opting out entails.

“Tracking refers to recording information so that somebody can link together activities by the same user over time,” said Edward Felten, chief technologist at the FTC.

Peter Eckersley, senior staff technologist at the Electronic Frontier Foundation, a watchdog group that campaigns for public rights in the digital arena, described the ad industry’s conflict about opting out.

“The industry has two radically different notions of what ‘opt out’ means,” Eckersley said. “One notion is that it means, ‘We’ll stop collecting records about you that we can use to track you’–the other definition is ‘We’ll just stop targeting ads based on the tracking we’ve done.’”

“It would be a mistake to write a piece of legislation that defines third-party tracking,” Eckersley added. “The better way would be to have an ongoing process for revising the definition. We know technology will evolve.”

As for current legislation, “there is no existing law at the federal level that relates to online advertising or third-party tracking,” Felton said.

Legislation has been introduced in California and at the federal level that would respectively give the state Attorney General’s office and FTC rule-making responsibilities, but nothing has been enacted.

“If the federal government were going to play a constructive role, [it should] create incentives for respecting consumer choice and for developing and respecting privacy-enhancing technologies,” Eckersley said.

Omar Tawakol, CEO of BlueKai, an online advertising company and NAI member that took overt steps to honor consumer opt out requests, illustrated the dilemma the industry faces.

“If you asked the consumer, ‘Do you want to get rid of advertising in your content?’ They’d say yes. If you asked them, ‘Do you want to pay for the content?’ They’d say no. Eighty percent [of content] is funded by some use of third-party cookie.”

Felten, Mayer, Tawakol and others representing online advertising and privacy interests attended WiTap, “Workshop on Internet Tracking, Advertising and Privacy,” hosted at Stanford by SSL on July 22.

Both Felten and Mayer spoke at the event, which was planned eight months before Mayer’s reports and addressed technical challenges in the industry and promoted research in the field.

“The main consensus [reached was] that privacy on the web…needs more research on both the technical and policy fronts,” Dan Boneh, professor of computer science and electrical engineering and one of the workshop’s organizers, wrote in an email to The Daily.

With regard to action resulting from the two reports, Felten said the FTC never reveals whether it is performing investigations but did address the technical ambiguities surrounding Mayer’s charge of “history stealing” by Epic Marketplace.

“[Epic] has objected to the term ‘history stealing,’ but the question is whether there’s a dispute about the technical details of what’s happening or not,” Felten said.

Eckersley thought the issue was clear regardless of technicalities.

“People are interested in whether these companies they’ve never heard of are sucking up all their reading habits like a giant vacuum cleaner or a creepy guy in the library looking over your shoulder at everything you’re reading,” he said.


Kristian Davis Bailey is a junior studying Comparative Studies in Race & Ethnicity. A full time journalist/writer and occasional student, he's served as an Opinion section editor, News writer and desk editor for The Daily, is a community liaison for Stanford STATIC, the campus' progressive blog and journal, and maintains his own website, 'With a K.' He's interested in how the press perpetuates systems of oppression and seeks to use journalism as a tool for dismantling such systems.

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