I made a thread about this in UI Discussion that got mostly ignored. I'm hoping you guys will have some 80 page argument about the chilling effects of implementing this feature and that ridiculous storm of arguing over nothing will get this suggestion noticed by devs.
EDIT: Ideally it would have a black list baked right into it. So an option that says "REPORT RMT" or something like that, or maybe something that brings up a window that lets you report racism, trolling, or RMT