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Study: Net crawling with hidden, snooping bugs

By Richard Stenger
CNN Sci-Tech

(CNN) -- A new report says the use of concealed bugs to collect information about online visitors has proliferated dramatically in recent years, in many cases on personal Web sites without the owners' knowledge.

Cyveillance, an Internet tracking company, on Tuesday released the report in which researchers say Web pages in 2001 are nearly five times more likely to include the hidden tracking devices than in 1998. And many of those bugs are said to reside on sites associated with well-known companies or products.

So-called Web bugs collect information similar to that gathered by banner advertisements, but users can't detect the presence of bugs without looking at the source code or using special software.

"One of most important findings was the presence of Web bugs on the home pages of leading brand sites," said study author Bryan Murray.

"Web bugs are an issue of controversy today -- whether it's ethical to use them or share the information with third parties. We wanted to raise the level of awareness of their use on the Internet."

One reported finding of the study, which looked at 1 million Web sites, is that the secret snoopers infest personal sites more often than commercial pages.

The bugs frequently appear on personal pages because sophisticated hosts or third parties like large community sites or ISPs offer free Web page-building tools to customers, according to the report.

"Most personal page owners are likely not aware that the Web bugs are present and collecting information from visitors," the report reads.

Third parties, including digital marketing companies, often place the bugs. They're also known as "clear gifs" and "Web beacons," and they monitor IP addresses, browser information and the surfing habits of visitors.

Unknowingly offering information

In some cases, Web surfers who provide personal information to one site, for example, to order a pair of tennis shoes, might unwittingly give a completely different Web site the opportunity to access their data, should both sites have bugs from the same marketing company.

Web bugs were found on 18 percent of personal pages and 16 percent of home pages affiliated with top corporate brands, the report says. The study found that the bugs, usually hidden as transparent, one-pixel-sized graphics, show up on 3.9 percent of all sites, compared to 0.7 sites three years ago.

Officials of some major ISPs say they use Web bugs to track consumer trends -- never to collect information about specific users. And online privacy advocates acknowledge that Web bugs have beneficial uses, such as monitoring copyright violations or gathering basic statistical information.

But the idea of a hidden infestation worries some electronic civil-rights advocates.

"Web bugs seemed to be used in a lot of places. Often companies will use them but imply in their privacy statements that they wouldn't use such things," said David Martin, an Internet specialist with the Privacy Foundation.

Great for 'beer money'

The co-founder of Be Free Inc., which places Web bugs on sites affiliated with AOL and other major companies, said his Internet marketing firm shares anonymous aggregate data with its partners, but does not gather or distribute any personal information. (AOL Time Warner is the parent company of

"We do not collect any user identifying information. We do not do that today and we will never do that, without explicit permission of users," said Tom Gerace. "We don't record name, address, phone number, credit card number, any of that."

Gerace took exception to the view that many personal Web pages had bugs placed on them without the consent of their authors.

"Where individual Web users have beacons, it is because the owners of those sites have placed them on their site to make some money," he said. "It's a great way to generate beer money."

If you'd like to keep the bugs away from your browser, consider checking It offers a free downloadable bug detector, created in part by Martin, which works with more recent versions of Internet Explorer. Turn down the volume on your machine, however. Every time it detects a bug, Bugnosis cries out, "Ah-oh!"

• Bugnosis Web Bug Detector
• Cyveillance
• AOL Time Warner

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