I've already posted a exploit days ago that i used to force "likes", you just have to incentivie the "like" click. Its TOS friendly & you don't have to worry about the ban hammer as much.
FB have to shoot on sight any malicious code, social engineering isn't a critical "duty of care" issue if your not a total muppet in your execution of idea.
I don't understand why people are bothering with fanpages any more, because if you open graph api your website you can actually get the same crazy viral growth, but you have less restriction on "how" you milk all the traffic.