Privacy advocates are asking the FTC to investigate the privacy implications of its Timeline and cookie use. (Justin Sullivan/GETTY IMAGES)

They would like the commission to determine whether the Facebook’s privacy policies sufficiently cover the company’s proposed changes. If not, the groups said, it could be violating U.S. consumer protection law.

Facebook came under fire again over privacy issues earlier this week when Australian blogger Nik Cubrilovic wrote Sunday about a discovery he made while looking into Facebook’s code. Cubrilovic wrote that the network was apparently tracking users’ Web consumption even after they logged out of the network. Facebook answered Cubrilovic’s concerns, he explained in a post two days later, by saying that the company has cookies that persist after logout in order to identify outside parties who may be trying to log in to a users’ account.

While Facebook said there were a couple of bugs in the system that kept unique user information, it said it did not store that information and has since fixed the bug.

Bugs aside, the network has also raised some eyebrows by introducing “frictionless sharing,” which will allow apps to post user activity to the network in real-time without requiring permission from account holders for every update. Some apps are already using the new platform, flooding Facebook users’ real-time feeds with information on what their friends are reading and listening to through the site.

The groups, which include EPIC and the American Civil Liberties Union, have also raised concerns about the Facebook “Timeline,” or revamped profile, which collects all of a user’s information on Facebook into a scrapbook-like page. “Timeline’s treasure trove of personal information can also provide a tempting target for stalkers, government agents, or employers,” the letter read.