We did, early on, get flooded by people who migrated en masse from another social network who - for lack of a better phrase - equated 'freedom of speech' with a right to post 'shock-and-awe' content just to get a rise out of others. They'd been run out of the other one and decided to try to take over ours.

Those of us running the site had a _lot_ of long philosophical discussions about what to do, but we ultimately realized that posting disturbing content with intent only to provoke wasn't constructive, and we had the right to define what type of community we wanted to foster.

So we booted the shock-jockeys out, and then went to an application-only process that lasted from 10,000 until about 100,000 users (that's a lot of hand-reviewed applications!) - and you know... I could still sleep at night after that, because it wasn't about stopping any specific cause or idea or viewpoint. (Indeed, a few came back, reapplied, and rejoined as constructive members of the community after that)

IMHO, there's a place for provocation, but only if there's a point to it - a message to be communicated. Random photos of animal heads in a jar with no commentary or explanation? Not so much.

I guess I thought of us as rather selective due to the application process, but as I think back, the application process actually allowed us to accept a much broader array of viewpoints, because our goal was always aimed at intentionality and constructive interaction.