Yes you can hack facebook games. I once found a way to download files from the game "pot farm" and got into there database.
I also owned a site (you need an account to see links) (now reowned) and made alot of cheats. Popcop games sent me a cease and disist letter after I hacked there game bejewlled blitz to give you unlimited time.
Aob is not a great method though theres other ways...