“Nobody is thought to be ignorant of the law”, or in US Law “Ignorantia juris non excusat”, “ignorance of the law does not excuse”.
In this case the law is the 1988 Malicious Communications Act, section1:
(1) Any person who sends to another person
(a) a letter, electronic communication or article of any description which conveys
(i) a message which is indecent or grossly offensive
(ii) a threat or
(iii) information which is false and known or believed to be false by the sender or
(b) any article or electronic communication which is, in whole or part, of an indecent or grossly offensive nature,
is guilty of an offence if his purpose, or one of his purposes, in sending it is that it should, so far as falling within paragraph (a) or (b) above, cause distress or anxiety to the recipient or to any other person to whom he intends that it or its contents or nature should be communicated.
(2) A person is not guilty of an offence by virtue of subsection (1)(a)(ii) above if he shows
(a) that the threat was used to reinforce a demand made by him on reasonable grounds and
(b) that he believed, and had reasonable grounds for believing, that the use of the threat was a proper means of reinforcing the demand.
(2A) In this section ‘electronic communication’ includes _
(a) any oral or other communication by means of a telecommunication system(within the meaning of the Telecommunications Act 1984 (c12)); and
(b) any communication (however sent) that is in electronic form.
(3) In this section references to sending include references to delivering or transmitting and to causing to be sent, delivered or transmitted and ‘sender’ shall be construed accordingly.
(4) A person guilty of an offence under this section shall be liable on summary conviction to imprisonment for a term not exceeding six months or to a fine not exceeding level 5 on the standard scale, or to both.
Liam Stacey made a number of comments on Twitter that were deemed to be offensive under the law. He can’t claim that he might not have known this law as that is no defense. He can’t say “Oh it was twitter”, because that is no defense. He can’t say it was PWI (Posting While Intoxicated) because voluntary drunkenness is no defense.
He was got bang to rights.
The plus out of all this is that we all know now what the law is and how it applies. Now no one has any excuse at all.
Abuse people online and you may face the consequences.
Damocles' Blog 
Stephanie
April 4, 2012 at 2:00 pm
He wasn’t charged under the Malicious Communications Act. He was charged under the Public order Act.
He didn’t claim to be ignorant of the law either.
This case is unprecedented because he received a jail sentence merely for a verbal abuse offence. Others have received community service or fines.
So why was it decided that it was so serious?
Well the judge gave an emotional and wildly inaccurate version of “public outrage” over his comments about a football player. It was like Princess Diana hysteria all over again.
The judiciary should not sentence people according to their heart but according to the law and justice.
The European Commissioner for human rights has condemned the sentence as “wrong”.
Damocles
April 4, 2012 at 2:12 pm
“He wasn’t charged under the Malicious Communications Act.”, He probably should have been. Anyway that was my understanding when I wrote the blog. I wouldn’t worry about it, barely anyone reads my blogs.
Damocles
December 17, 2012 at 8:29 pm
“barely anyone reads my blogs.”
Since making that comment this has become my 5th most read blog.