Fun fact for you: in 2012, 653 people were charged with various offences relating to stuff published on Twitter and Facebook. There's a whole range of laws you can fall foul of when joking about on social media, and some of them can even land you with jail time.

 

Libel

Unless you spent the latter half of 2012 in a fallout shelter awaiting the apocalypse, you almost certainly heard about the case of Lord McAlpine and Sally Bercrow. No? Well, to cut a long story short: in November last year, a BBC report 'suggested' that a senior Tory party member had molested a child; it didn't name which one, but the hive mind of Twitter did.

Lord McAlpine described it as "trial by Twitter", and instructed his lawyers to sort it out. Branding someone as a child molester without evidence certainly falls foul of libel laws. According to the BBC, a tweet may be considered libellous if:

"it damages someone's reputation "in the estimation of right thinking members of society". It can do this by exposing them to "hatred, ridicule or contempt". It is a civil offence so you won't be jailed but you could end up with a large damages bill. The rules also apply to re-tweets."

Basically, if you make serious, unfounded and false claims about somebody (that's factual claims, not your own opinion), a civil court case for libel can be brought by whoever it is you've been slagging off.

That doesn't mean that everyone can be nailed for libel. In the McAlpine case, only Twitter users with more than 500 followers were being pursued by lawyers; in general, the smaller the reach you have, the less likely you are to be prosecuted -- it's the difference between insulting someone on live TV with an audience of millions, or saying something in the pub, basically.

Libel is a civil offence, which means that there's no jail time involved, but the fines can still be pretty hefty. In the case of Sally Bercow, she's being sued for £50,000 in damages; other libel cases can be even bigger -- the Sunday Times was sued for nearly £1m by Lance Armstrong (oh, the irony) when it called him out for doping back in 2004.

 

"Grossly Offensive" Messages

Yes, it's also offensive to publish tweets which are "grossly offensive or of an indecent, obscene or menacing in character". (In fact, it's illegal to send messages of that nature over any 'telecoms network' -- so don't text instead of tweeting!)

There have been a shedload of cases involving this law in the last twelve months: in July, a 17-year old was arrested for abusing Tom Daley on Twitter; a man was jailed for 12 weeks for posting offensive remarks about Madeline McCann in October last year, and another guy got a community sentence for posting pictures of himself burning a poppy.

Once again, the "reach" of the offensive messages has an impact on whether or people will be prosecuted. The Crown Prosecution Service is in the middle of a review into the matter, but according to its interim guidelines, cases involving users with thousands of followers are more likely to be dealt with. Remember, though, that it's discretionary -- so even if you've only got three lonely people following you, think twice before posting threats. Maybe make a nice pot of camomile tea instead.

And yes, once again, re-tweeting something grossly offensive is also committing an offense. Remember, the RT button is not your friend!

 

Contempt of Court

The thing that's all over the news this morning is the forthcoming prosecution of Twitter users who circulated photos of James Bulger's killers, Jon Venables and Robert Thompson.

The reason that this is an offence (and a criminal one at that) is because there's a court order in place that bans identification of those two, in order to protect them from vigilante attacks and to allow them to start a new life under a new identity. Even though the people who were circulating the photos probably didn't know that there was a court order protecting the identity of the pair, they're still breaching said order, and as such are in contempt of court.

This is the first case of its kind, so it's uncertain what the punishment will be; in other cases, though, contempt of court can carry jail terms of a couple of months.

 

Reporting Sex Offences

This is another case where identifying people on social media can get you in the doodoo. In April 2012, a footballer was convicted of raping a 19-year-old woman. Under the Sexual Offences Act 1992, media organisations are automatically banned from naming the victims of sexual offences; turns out that social media users are under the same restriction.

In this case, a total of nine people were fined by magistrates.

 

How to Avoid Getting in Trouble

Although there's a bunch of different laws that Twitter users often fall foul of (the ones listed above are the most common, but by no means a definitive list), the general principles involved in not having a run-in with the law are quite simple:

- Don't name people in court cases who haven't already been named by mainstream media. If the BBC is reporting on a case and refers to someone as "Person X", there's probably a reason for that. If you happen to know who Person X is (I don't know, maybe you're a bit of a creepy stalker), keep it to yourself.

- Don't share your random guesses about who might be sex offenders. It's called libel. It might be fine to gossip about this sort of thing in the pub, but when you're sharing on Twitter for all to see, be a bit more discerning.

- Be careful about who you re-tweet. We didn't even want Sally Bercow clogging up our Twitter feeds anyway. Just count this as a good excuse to cut down on the amount of crap you re-tweet.

- Don't be a Twitter troll. This one is more life advice, but anyway: try not to gratuitously insult people you don't even know. I know it's hard to keep the pent-up internet rage at bay, but just try, mkay? And if you've really got to pick on random people, well, that's what 4chan is for.

- Don't joke about blowing airports up. I don't think this one needs any explanation.

Disclaimer: I'm not a lawyer, so don't take this as gospel truth, and no blaming me if the Crown Prosecution Service comes after you anyway. For more information, have a look at this excellent BBC guide.