Forget shitposts, there were legitimate flame wars in Pompeii graffiti:
Successus textor amat coponiaes ancilla(m)
nomine Hiredem quae quidem illum
non curat sed ille rogat illa com(m)iseretur
scribit rivalis vale
Translates to:
Successus the weaver is in love with the slave of the
Innkeeper, whose name is Iris. She doesn't care about
him at all, but he asks that she take pity on him.
A rival wrote this
A response to this translates to:[6]
You're so jealous you're bursting. Don't tear down
someone more handsome―
a guy who could beat you up and who is good-looking.
There have been examples that are effectively primitive shitposts found carved into walls in Pompeii. People never really change.
Forget shitposts, there were legitimate flame wars in Pompeii graffiti:
https://en.wikipedia.org/wiki/Roman_graffiti