Guess I could have just googled it. It appears FBI can access that info:
"Even though your online crush doesn't know you're watching them, Facebook does. "We receive data about you whenever you interact with Facebook, such as when you look at another person's timeline, send or receive a message, search for a friend or a Page, click on, view, or otherwise interact with things, use a Facebook mobile app, purchase Facebook Credits, or make other purchases through Facebook.... Typically, information associated with your account will be kept until your account is deleted," Facebook writes on its website.
Where is this data kept? On servers stored miles below the earth, in bulletproof vaults, guarded by angry #3b5998-blue cyborg gnomes who hop from leg to leg wielding torches and spears? Actually, Facebook has data centers around the world, and they are fancier than your house.
Of course, the FBI can also access your Facebook records, but this is probably most relevant only if you're engaging in criminal behavior (advice: don't)."
link:
http://www.fastcompany.com/3000466/facebook-voyeurism