@LiterallyStockfish Interesting, thanks. I would slightly debate the first point. IF it was (insert lawyer terms) "fully understood that it was indeed (famous player) and everyone treated him like the person who he is" then I could see him saying his online identity is really who he is. Say he sells books, owns a chess site, his life earnings are based on chess......and i think it can't be impossible to find out who is on the other side, but maybe it's hard. again, is it malicious? that's up for the court. and if anyone believes the person, but there would have to be direct loss that's proven. but if you go after me, then it depends what country we are in. some countries are strict, and others not so much. and then it would take time, money, effort, etc......so probably doesn't matter if you accuse me in a country that is harsh on defamation and libel, unless i was a big shot in that country. if some joker accused a super famous player, and it got traction in social media, i'm fully convinced we would find out who said it.
ok, my point.... maybe there are only a few players where you might not want to accuse without significant proof.