The only methods of enforcement between sites were either personal favors or the nuclear option of not peering.
But, The Cabal (which does not exist,) would smack people down if they became too outrageous. Not mere assholes, but people who ruin the commons for everyone...
So yeah, there was never a free internet. Just a Cabal (There Is No Cabal) of Admins who were more interested in keeping the system running than policing speech.