Can you get a restraining order against Web ads that stalk you?

Linda Musthaler
By | September 07, 2012

Posted in: Network Security Trends

Have you ever had that feeling that you’re being followed? How about when you’re sitting at your own desk, surfing the Web?

A few months ago, I was shopping for a necklace for my daughter. I was looking at some nice choices on and ran out of time for shopping. I closed my session without buying anything. The next day I logged onto to my email hosted by Yahoo. And there it was, lurking in an advertising frame on the left side of the screen—the exact necklace I had my eye on the day before. In fact, was serving up an ad featuring several of the necklaces that I had looked at. When I saw that, I was very creeped out. I felt like I was being stalked. (Cue the Twilight Zone music now.) I knew that online advertising had been growing more targeted, but I didn’t realize it had reached that level. It’s called Online Behavioral Advertising (OBA), or Interest Based Advertising, and it’s very prevalent today.

OBA tailors online advertising to individual users based on Web pages they have previously browsed. As a person surfs the Web, in particular ecommerce sites, the websites place cookies on his computer. The cookies contain tiny bits of information about the person’s surfing behavior. In my case of shopping on, the website dropped a cookie on my PC for each necklace I viewed. Then an advertising network hired by Overstock collected enough information from those cookies to know what I was interested in—in this case, the specific necklaces I had viewed. The advertising network used my next browser session (which happened to be for checking my email) to send me customized ads pertaining to my interests. (For a more thorough explanation of how OBA works, view this Wall Street Journal video on how advertisers use Internet cookies to track you.)

This concept is great for marketers who want to target their prospective buyers with truly useful ads. But how do consumers feel about such customized advertisements? It turns out that I’m not the only person who feels like it’s a form of stalking.

Carnegie Mellon University’s CyLab conducted a research study about consumers’ perceptions of OBA and their concerns about privacy. CyLab published the study results in the report Smart, Useful, Scary, Creepy: Perceptions of Online Behavioral Advertising.

In August 2011, researchers selected 48 participants to go through a 90 minute combination interview and usability study. While the participants were knowledgeable on how to use a computer, none had a degree or job in computer science or information technology. In other words, they are average computer users.

Of the 48 participants, none was aware of OBA or how it works. This is a concern because the online advertising industry is self-regulating in terms of use and abuse of OBA, and one of the basic principles for advertisers to follow is the “education principle.” That is, websites that use cookies to track a person’s online behavior should educate that person about the generation of cookies and how they may be used in the future. These same websites are supposed to clearly explain how users can opt-out of cookie collection and OBA. (In the case of, this information is explained in the company’s privacy and security policy.)

The CyLab researchers showed the study participants the Wall Street Journal video that explains how cookies are used to track people. Having viewed the video, all of the participants felt that this practice is an invasion of their personal privacy. Many of them were concerned about being tracked on the Internet. Further, despite the fact that cookies used for OBA do not collect personally identifiable information or financial information in any way, the study participants had a concern about having their financial information or identity compromised by this practice.

Clearly there is a need for broader consumer awareness and education about tracking cookies. People need to be made aware that this is happening as they surf the Web, and they need to know how to control or opt-out of the practice. Consumer education is posted on but it isn’t reaching a broad enough audience. The U.S. Federal Trade Commission has called on the online advertising industry to give consumers greater control over the collection and use of their personal data through simplified choices and increased transparency. Consumers should have a reasonable expectation of privacy as they surf the Web, and they shouldn’t feel creeped out by ads that seem to stalk them.

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