Most reasonable people are aware that if you publicly publish something defamatory about someone else that is false, you can be sued for libel. If you lose the legal case, it can be expensive for you in terms of damage to your reputation as well as a financial cost. (Related: the difference between libel and slander in UK law.) And I’d add that most reasonable people are also aware that the same rules on libel apply to all methods of public communication, including online. …