Google says it is working to shore up its ability to keep its users' web habits under wraps. The search giant keeps terabytes of data about its users' surfing habits, collected through legitimate means such as the optional feedback function within the Google Toolbar .

This information includes web addresses visited, search queries used and the cookies left on users' machines. It says it is concerned that the information could potentially be used to identify individuals.

"When you search on Google, we collect information about your search, such as the query itself, IP addresses and cookie details. Previously, we kept this data for as long as it was useful," said a statement by Google lawyers Peter Fleischer and Nicole Wong.

"Today we're pleased to report a change in our privacy policy: Unless we're legally required to retain log data for longer, we will anonymise our server logs after a limited period of time."

The company says it will "continue to keep server log data" but is aiming to "make this data much more anonymous, so that it can no longer be identified with individual users, after 18-24 months."

Google says it "works toward having the best privacy practices for our users". The statement cited features such as Google Talk's 'off the record' chatting, or the ability to momentarily suspend the feedback to Google in Google Desktop.

The statement does say that some services need Google to have access to more data. But this is optional - you can opt for Google to keep all your information "for more personalised services like Search History". But, says the company, "that's up to you".