Oh, dear god, no - have you ever used Reddit? This is what happens when you outsource moderation to the sorts of users who enjoy moderating other people.
Very completely different things. Subreddits would be the equivalent of Facebook Pages and they already have moderation tools for those that run the page.
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Hello user, you have been randomly selected to help moderate.
Does this depict pedophilia? Y/N
[ Image here ]
This image was flagged by other users as depicting horrible gore and death, do you agree Y/N?
[ Image here ]
This post may contain hate speech, do you agree? Y/N
[ Embedded Nazi Screed post ]
Thank you for making Facebook a safer place for everybody!
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"Facebook made me look at child porn" is probably a headline Facebook would prefer not to have going around.
Would that be expensive at the scale required by Facebook? Very.
Personally I'm fond of zucc-bux
Overall not possible. On Slashdot everything is basically public, on Facebook it's largely private/restricted and I'm sure from past discussions that the worst stuff is in private groups or clusters of friends. They could do much more aggressive banning of users (and detecting new accounts designed to circumvent bans) for sharing such content or being in groups focused around such content, but that might hurt their most important metrics.
So yeah, it was tongue in cheek, with a side of reductio.
I'm not saying if Sally starts a forum and it gets hacked and someone posts illegal stuff she should be fined or charged with anything. I'm not saying she should even be in trouble if she gives one person who turns out to be a jerkass posting rights and that person posts illegal stuff. But if she opens up public signups, gets a billion or two users, then says "well I guess I'll just have to pay a bunch of people money to look at all this gore porn that's getting posted" the rest of us should go "uh, no, you should instead just stop".
[EDIT] and given that second sentence, no, I'd get nowhere in American politics.
Of course the real answer is that this sort of site is a bad idea and shouldn't exist. Wide-open signup and public visibility of content, or ease of sharing it with strangers. Bad combo, don't care how much money it's making them (and other, similar sites).