29/01/2014 10:47 GMT | Updated 31/03/2014 06:59 BST

The Real Reason Those Sad Twitter Trolls John Nimmo and Isabella Sorley Were Sent To Jail

As someone who is generally opposed to the imprisonment of Twitter trolls who spew out ghastly nonsense online, I have found myself in a fair few debates about John Nimmo and Isabella Sorley over the past few days.

Mr Nimmo and Ms Sorley are, respectively, the "social recluse" and young woman with drink problems who last Friday were sentenced to around two months in jail for sending disgusting tweets to the feminist Caroline Criado-Perez and others.

Everyone I have discussed this case with has said the same thing: "Look, Brendan, they weren't jailed for expressing their opinions. They were jailed for making death and rape threats, which, duh, is against the law." The media headlines confirm that view. This is being talked about as a very simple case: these two idiots made death threats, it's an offence to make a death threat, hence jail.

It is true that it is against the law in Britain to threaten to kill or assault someone, as it absolutely should be. If I were to go on a radio show and say to the presenter, "I am going to murder you", I wouldn't be exercising my age-old right to free speech - I would be committing common assault, putting someone in fear of an immediate act of unlawful violence, and I could face arrest.

But here's the thing: Mr Nimmo and Ms Sorley were not tried or found guilty under any of the acts of law which, rightly, make it an offence to threaten to kill or assault someone. They were not found guilty of making a death or assault threat.

It is the Offences Against the Person Act which makes it an offence to "write" or "utter" a death threat. "Whosoever shall maliciously send, deliver, or utter, or directly or indirectly cause to be received, knowing the Contents thereof, any Letter or Writing threatening to kill or murder any Person, shall be guilty of a Felony", that act says. Mr Nimmo and Ms Sorley were not brought to court under that act.

It is case law, as codified in the Criminal Justice Act of 1988, which has made it an offence to carry out the common assault of making someone fear "the immediate use of unlawful violence". But Mr Nimmo and Ms Sorley were not tried or found guilty under the Criminal Justice Act 1988 either, and nor was case law on common assault cited in the reasons for their conviction or imprisonment.

So to say that Mr Nimmo and Ms Sorley were imprisoned for making threats of murder or assault is plain wrong, since they were not tried or jailed under either of the acts or any of the laws that forbid the making of such threats.

Just consider their prison sentences - eight weeks for Mr Nimmo and 12 weeks for Ms Sorley. The Offences Against the Person Act says those who issue death threats should be imprisoned for a term "not exceeding ten years and not less than three years". If Mr Nimmo and Ms Sorley really had been found guilty of the very old, very serious offence of issuing a death threat, we could expect that they would have been sentenced to jail for much longer than a couple of months.

No, these two individuals were found guilty of an offence under the Communications Act of 2003. This act makes no reference to death or rape threats, which do not fall under its purview and which it does not punish.

Mr Nimmo and Ms Sorley were found guilty of behaviour that is contrary to section 127 of the Communications Act, which makes it an offence to "send by means of a public electronic communications network a message or other matter that is grossly offensive or of an indecent, obscene or menacing character". That is, they were found guilty of sending a message, not making a threat; they were found guilty of saying something that was "offensive, indecent or menacing" in character, not of committing the offence against the person of threatening to kill another individual. They were found guilty under a law which criminalises speech, not assault.

I cannot be the only person who finds that section in the Communications Act worryingly broad - it criminalises not just the sort of menacing tweets sent by Mr Nimmo and Ms Sorley but also messages that are "grossly offensive" or "indecent". Who judges what is offensive and indecent? Judges, it seems. Police and old men in courts. It is not too fanciful to imagine someone being hauled before the courts for emailing to Muslims horrible cartoons of Mohammad ("grossly offensive") or for posting on Twitter a pornographic image ("indecent"). Just because we can all agree that what Mr Nimmo and Ms Sorley said in their tweets was horrendous doesn't mean we should give a slavish nod of approval to the law under which they were found guilty of an offence and jailed.

So, to all those people saying, "This isn't a free speech case, they were simply jailed for making death threats!", I say: "Not so fast..." Firstly, because they were not found guilty of committing the old offence of "threatening to kill or murder any Person"; and secondly, because the act that they were found guilty under does, very clearly, have implications for free speech - for everyone's free speech, not just the speech of sad, pathetic trolls who bombard women with vile messages.