A civil post on Facebook or whatever is OK, even flyers to a degree. BUT You cross into Karen Territory if you go overboard on either. just use discretion. :]
You should always remain professional and cordial, even when dealing with scammers. Never threaten. That can be considered harassment and extortion even though he started it
Do not be surprised if what you sent flames the situation. not advertising on Craigslist is hardly a penalty, don't be...