Say I pay you to walk into a pub and tell your friends about my favourite candidate. Your pub generally disallows advertising. But they can't really detect this. So they don't actively do anything about it the way they do some guy walking in with a sign. That's the situation.

Solution: As a pub you have users sign a terms of service before letting them in, stating that you don't allow this type of behavior and reserve the right to ban the advertiser and the messenger from entering the establishment.

Then you make it easy to report solicitation of any activity that's against your terms.

A single person might be able to slip by, but anyone trying to brainwash your patrons at scale is very likely to get caught.

> A single person might be able to slip by, but anyone trying to brainwash your patrons at scale is very likely to get caught.

Sure, but a slight correction here. You're implying that once they're caught, they lose. But that's not what happens. To continue the bar analogy, the bartender now has to start banning his customers. He can't do anything to the guy that's bribing them.

Bloomberg got "caught" but that doesn't matter at all to him.

In this case the guy bribing people is also a regular at the only two pubs in town and getting kicked out of one of them would tank his venture because it's a source of a large portion of his audience.

Bloomberg getting kicked off of the Facebook ad platform would be a huge blow to his campaign. Facebook is huge for political campaigns because it allows them to micro target their audience and spam them with ads without any intent on the receiving end.

EDIT: Anyways, my main point is, if Facebook wanted to solve this problem they would.

If they cared about this problem to the exclusion of all else, sure. But Facebook doesn't want to ban all mention of Michael Bloomberg since Facebook users want to talk about him.