While most search engines offer researchers some access to their data (both Google and Microsoft do this, for instance), they also recognize that releasing the complete search history of 500,000 users from March to May of this year might pose certain privacy risks.

Not AOL. The newly-free service posted a complete three-month set of search queries on Sunday, only to take it down several hours later. By that time, though, the data was already in the wild—and what interesting data it was.

AOL did replace usernames with random numbers in a bid to protect privacy, but because each user’s queries were given the same random number, it was simple to see a person’s complete search history.

Source: arstechnica