Google announced Thursday that it will change its privacy policy to anonymise retained server logs after an 18-to-24 month period.

Google collects identifiable information with each query it receives, including IP addresses and cookie details which it then uses to improve the search products.

This information is used to refine the paid search engine items that appear with a user’s search to match with geographical information, Google has said.

"After talking with leading privacy stakeholders in Europe and the U.S., we're pleased to be taking this important step toward protecting your privacy," Google announced on its website. "By anonymising our server logs after 18 to 24 months, we think we’re striking the right balance between two goals: continuing to improve Google’s services for you, while providing more transparency and certainty about our retention practices."

Google is planning to implement the changes by the end of the year.

A Google representative could not be reached for comment on Thursday.

Some privacy advocates said this shift is not enough, claiming Google shouldn’t collect the correlation data at all.

"We think they shouldn’t be keeping this data at all," said Paul Stephens, policy analyst for the Privacy Rights Clearinghouse. "The fact of the matter is, as long as that information is retained, it is subject to be secured through judicial processes. And as we know, there have been abuses of that sort of thing in the past."

The Privacy Rights Clearinghouse's position on the matter is that Google should allow users the choice to opt in before collecting their information.

John Soma, executive director of The Privacy Foundation and law professor at the University of Denver, said Google’s announcement was at least an improvement, though he wonders if the motivation is really about consumer interests.

"Well, first of all, it is clearly a move in the right direction," he said. "Second, I doubt if it’s a total charity on their part. When you look at the Patriot Act and other issues of police investigative work, they may be just saying the value of the data is down low enough, and now if we keep it for a long period then somebody from the FBI is going to be knocking on our door. And therefore if we don’t have it for everybody we can say, ‘We’ll give you the last 18 months and please leave.’ They are at least eliminating the deep searches back."

In its announcement, Google said it would retain data for longer periods of time if legally required to do it.

"In the future, it's possible that data retention laws will obligate us to retain logs for longer periods," Google said.