AOL Search Queries Open Window Onto Users' Worlds

Boutin also works for a start-up in Silicon Valley that makes software to sift through computer-generated search logs. "If you look at search logs for even a few weeks, you've seen every crazy search term you can imagine," he said. "The only interesting thing left is what are the large-scale and long-term patterns in this data."

For instance, he said, do ad campaigns actually drive people to search for things? Did Chrysler's "Ask Dr. Z" sweepstakes move people to look up Dr. Z online? It's useful stuff for marketers, he said.

Matthew Hindman, a political science professor at Arizona State University, said, "My first reaction was horror at the privacy implications," he said. "And then I got excited about all the fun things we could learn from the data."

For instance, he said, which search terms are people using to find Web sites with political content such as gun control, abortion or campaigns? That's usually difficult to determine because political Web sites generate a small percentage of all Internet traffic.

"Having this great mass of raw data from average users really is a great opportunity to find out about how citizens search," he said.

It is also useful to research the claim, he said, that the Internet is part of a communications shift from broadcast to narrowcast, from the era of Walter Cronkite to an era of podcasts and online news. Both Republican and Democratic political consultants, he said, have argued that a changing media environment necessitates a change in campaign tactics -- giving more power to small-scale news producers.

AOL's own researchers published a paper, posted online before the data breach, called "A Picture of Search." They found, among other things, that the most frequently searched subject category -- about 15 percent of queries -- was "other." That means that most searches were so diverse they could not be categorized. Entertainment was next, followed by shopping, with pornography at about 7 percent.

AOL declined to make its researchers available for comment.

The Electronic Frontier Foundation this week filed a complaint with the Federal Trade Commission alleging that AOL violated its privacy policy and deceived users about how their data were being used. The San Francisco advocacy group provided examples of search strings containing sensitive personal terms that could be linked to individuals. It was unclear whether the individuals were the users themselves.

Asked whether the research benefits outweigh the privacy implications, Hindman said no. "This sets a terrible precedent, and the hope is that other companies will learn from this mistake and put much stricter guidelines on how search data such as this is handled," he said.

But he said he is still going to use the data because "it seems pretty clear the damage is already done."

Research database editor Derek Willis and news researcher Madonna Lebling contributed to this report.