In what could only be considered a privacy nightmare, AOL has released search logs of over 658,000 users. From the CNET news article:

Although AOL had used identification numbers rather than names or user IDs when listing the search logs, that did not quell concerns of privacy advocates, who said that anyone among the 658,000 could easily be identified based on the searches each individual conducted.

Though AOL has now taken down the data, it’s already too late. The data is currently available through Mininova, USENET, and other distribution channels. Greg Sadetsky provides mirrored links to the now defunct AOL data.