Well it all started when ███ ██████ wasn't a fan of ███'s dirt sculpture called ██████ and the █████████ and so stomped it into oblivion.
In all seriousness censorship has a rather long and storied history, no doubt much of it rather unwritten! One thing I learned about earlier this year during my research was that the Romans used to have electable Censors who actively regulated the Regimen Morum, or Public Morals.
They were known as the "Chastisers" and in addition to their census taking activities, their punishments could follow from a fun list of things like taking on a disreputable trade such as acting, being single, divorcing your spouse for insufficient reasons, simply being rude to a magistrate, or letting your fields grow unseemly.
Their work also aimed to punish people for acts such as spousal abuse, the abuse of one's slaves, lavish living, defrauding orphans, and the neglect of military horses.
You can read more about it on Wikipedia, but this really is just the tip of the iceburg for how vast the role of censorship has played in societies of the past https://en.wikipedia.org/wiki/Roman_censor#Regimen_morum