Google now expires cookies after 2 years, not 31

Google relies on what they call their PREFS cookie to remember information about visitors -- their cookie is set to expire in the year 2038, and some privacy advocates say that violates the privacy of users. That said, users have complete control over the cookies on their machine through browser settings already, but Google decided to cut the expiration time 29 years to just 2. Privacy watchdogs should have something good to write about[PDF] now, but they probably won't.

In the coming months, Google will start issuing our users cookies that will be set to auto-expire after 2 years, while auto-renewing the cookies of active users during this time period. In other words, 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. And, as always, all users will still be able to control their cookies at any time via their browsers.

On the other hand, I don't still understand why they need a two year expiration if they are auto-renewing them. Why not set it to something like 6 months -- if a user doesn't visit Google at least once in that amount of time, they aren't a regular user so why bother remembering them? What do you think? Are you more comfortable with cookies that expire in two years?