This came up years ago when Facebook had its hearings about the difficulties of content moderation. Through hundreds of billions of pieces of content you're going to end up with a millions of NSFL BLITs. Of those even if .1% requires a human to determine whether or not it's unsafe, thats still a thosand moderators who've had their day ruined.
So apparently the response so far has been to outsource to undeveloped countries to ruin their lives.