There is a 550+ page flat earth thread in OT (and I would guess 80% of it is redundant in itself LOL). There is a ~7 page flat earth thread in P&S. I even posted in the P&S thread advising to use the OT thread (as it's much bigger and funnier!) but still page after page of shit posts rack up in the P&S thread. So it seems the logical thing to do is lock the P&S thread and encourage (with a link) anyone interested in talking about the topic to go to the Off Topic thread for further discussion.
Obviously this is one I know about and I am sure there are tons more so the mod in that section will need community support to be effective.