Funnily enough, the currently airing Starz program, Spartacus: House of Ashur does this, has Caesar as a character and all political sides use “pirates” as a bogeyman to justify all sorts of things and stage false flag attacks while pretending to be pirates. It’s meant for entertainment not historicity but it’s kind of reminding me of Battlestar Galactica reboot touching political themes in this one aspect except with swords and prosethetics flying everywhere.

I saw an exhibition on cannibalism that mentioned a similar thing such that being called a "cannibal" was used in a similar fashion.