From an EPIC (Electronic Privacy Information Center) Blog Post:
The White House modified its privacy policy for WhiteHouse.gov on June 3, 2011. The new policy is more than twice as long as the old policy. The new policy states the White House web site now uses persistent Google Analytics cookies that track users for up to two years. Previously the site employed only single-session cookies, which were automatically deleted when users closed their browsers. The site does not provide a means for visitors to opt out of receiving cookies.
The complete EPIC blog posts contains a couple of additional links links.

