Good point. But we should notice anonimity is being abused now, there are anonymous war hawks everywhere, folk are being terrorised into never calling them out because who knows who or what might be behind the mask, they seem well informed, inside views of the killing machines.
Hence why my own policy is just keep repeating to folk taking them seriously, "Never trust a ghost".
Personally I see use of pseudonyms in supposedly serous, or emotional conversations as dishonest, it's a basic covering up of truth, that removes the person behind the mask from feeling any responsibility with no skin in the game themselves.
But it's more a social responsibility to never take ghosts seriously rather than a state or police matter, removing all possibility of anonymity by force would be a very bad move, I agree with you.