Googleis reversing a long-standing policy to retain all the data on its users indefinitely, and by the end of the year will begin removing identifying data from its search logs after 18 months to two years, depending on the country the servers are located in.
Currently, Google retains indefinitely detailed server logs on its search engine users, including user's IP addresses – which can identify a user's computer, the query, any result that is clicked on, their browser and operating system, among other details. Even if a user never signs up for a Google account, those searches are all tied together through a cookie placed on the user's computer, which currently expires in 2038.