Google reduces cookie lifespan by 30 years

Google has tipped its hand to privacy advocates and agreed to cut the lifespan of user cookies by up to 30 years -- instead, the search giant will implement a rolling two-year auto-renew policy.

Cookies are small files stored on a computer so that it can be recognised when it revisits Web sites, enabling the site to remember the user's preferences for things like e-commerce and sites that require log-in.

Under the new policy, Google cookies will expire after two years instead of in 2038, according to the official Google Blog.

"After listening to feedback from our users and from privacy advocates, we've concluded that it would be a good thing for privacy to significantly shorten the lifetime of our cookies -- as long as we could find a way to do so without artificially forcing users to re-enter their basic preferences at arbitrary points in time," writes Peter Fleischer, global privacy counsel.

"Users who do not return to Google will have their cookies auto-expire after 2 years. Regular Google users will have their cookies auto-renew, so that their preferences are not lost."

In practice, however, only a miniscule number of people will be affected by the change. That's because if anyone visits Google even once in the next two years, the cookie expiration date will be extended. In other words, visiting on July 16, 2007, will reset the cookie to expire around July 16, 2009. Visiting any time between those two dates will automatically extend the life of the cookie -- renewing it, effectively -- for another two years.