[tathougies]

> Prove me wrong

Well, there's really nothing to prove. You didn't make the claim that 'the earth is flat'. Instead you made the claim that 'My [papito's] opinion is that the Earth is flat'. There is no reason to disbelieve the latter. It is clear from your own statement that your opinion is that the Earth is flat. There is no reason to counter that statement.

This is why facebook has no obligation to do anything. Facebook's entire platform is to allow various entities to self-publish their opinions. If it is clear that this is your opinion on hacker news (where the anonymous username is actually relatively obscured compared to facebook's real name policy and name placement), then it is extremely clear on Facebook.