According to this WaPo article:
AOL issued an apology yesterday for posting on a public Web site 20 million keyword searches conducted by hundreds of thousands of its subscribers from March to May. But the company’s admission that it made a mistake did little to quell a barrage of criticism from bloggers and privacy advocates who questioned the company’s security practices and said the data breach raised the risk of identity theft.
“This was a screw-up and we’re angry and upset about it,” the company said in a statement. “Although there was no personally-identifiable data linked to these accounts, we’re absolutely not defending this. It was a mistake, and we apologize.”
The posted data were similar to what the U.S. Justice Department had been seeking when it subpoenaed Internet companies, including AOL, last year. AOL complied and handed over search terms that were not linked to individuals. Google Inc. fought the subpoena in court and won.
The AOL data was posted at the end of last month on a special AOL Web site designed by the company so researchers could learn more about how people look for information on the Internet. The company removed the data over the weekend when bloggers discovered it. …
Later the article notes: “Some bloggers said some of the information available included queries on how to kill one’s spouse and child pornography.” I’m not surprised, as search terms that lead people to this blog this very morning included: “naked Germaine Greer”and “are beards attractive to teenage girls.” In any event, it’s yet another reminder that there is no anonymity in cyberspace.