Probably not the ones—if any—that lurk 4chan and other extreme imageboards, having been desensitized to such content or probably even get something off of it.
I actually wonder now how much of their workforce would fit in that demographic.
I was just thinking that. 4chan janitors are volunteers. Of course, the payoff is helping 4chan exist, not helping Facebook make a few billion more, so the incentive is still vastly different. Still, that might be the right recruitment pool.