I am sorry to disappoint you, but posting nasty comments is a crime in the UK under the 2003 Communications Act, which means it has been a crime for decades.
Section 127(1) makes it an offence to:
"Send by means of a public electronic communications network a message that is a -
(a) grossly offensive,
(b) indecent, obscene, or menacing, or
(c) false, known to be false, for causing annoyance, inconvenience, or needless anxiety."
Section 127(2) adds that: "A person is also guilty of an offence if they cause a message or other matter to be sent that is similarly offensive or menancing.
