This week a man was convicted of sending an online death threat to Corby MP Louise Mensch concerning one of her children.
Sixty-year-old Frank Zimmerman first contacted her via Twitter using a pseudonym claiming he had information about the phone hacking scandal.
Mrs Mensch sent him her personal email address and it was to that account that Zimmerman sent the threatening message, telling her she would have to choose which of her three children would die.
He wrote: “We have sent a camera crew to photograph you and your kids and will post it all over the net, including Twitter.
“You now have a Sophie’s Choice. Which kid is to go? One will, count on it.”
The MP took the threat seriously and contacted the police.
Zimmerman was this week convicted of sending by public communication network an offensive, indecent, obscene, menacing message or matter and will be sentenced next week.
This is the latest in a series of cases that highlight the implications of posting inappropriate and offensive messages online.
Last month saw the first ever Twitter libel case when former New Zealand cricket captain Chris Cairns was awarded £90,000 after he successfully sued Lalit Modi, former chairman of the Indian Premier League. Modi had posted a 24-word message on Twitter in January, 2010, accusing Cairns of a past record of fixing.
Also last month student Liam Stacey was jailed for 56 days after posting racially offensive comments about footballer Fabrice Muamba.
Stacey admitted a charge of inciting racial hatred through his tweets, which he posted just after the Bolton Wanderers player collapsed during an FA Cup match against Tottenham Hotspur.
The Crown Prosecution Service says cases like this should serve as a warning to people about what they say online.
Nick Hawkins, of the CPS, said: “Harassment through social media is covered by existing legislation, such as the Misuse of Communications Act, and we have already seen successful prosecutions in this area.
“Where the abuse is racist, we can bring that to the attention of the court as an aggravating feature.
“This is an area where I would suggest education, both of what not to do and of how easy it is to detect and prosecute these offences, might prevent the criminalisation of otherwise decent people, but I should stress I would never condone the misuse of social media to commit what would be a hate crime if said face to face.”
So what can and can’t you say on social networking sites like Twitter?
Half of Twitter users don’t consider whether their Tweet is in breach of the law before sending it, while two-thirds have little awareness of their legal rights and responsibilities when posting to social media, according to a study by law firm DLA Piper.
Twitter makes a point of saying it is not responsible for the content of its users’ posts and says it firmly believes in free speech.
The general manager of Twitter in the UK, Tony Wang, said last month that Twitter takes a “neutral” view of messages posted by its users because the social network sees itself as “the free speech wing of the free speech party”.
But the basic rules regarding libel and defamation apply to online blogs and posts just as they do the spoken and printed word and violating these laws can land you in serious trouble.
Sue Oake, senior legal advisor at the Newspaper Society, said: “Everything that applies to the printed press also applies to digital publishing. “That was one of the early myths that has taken a long time to go, people assumed the internet was a law-free zone.
“All of the libel laws and contempt of court laws apply equally to publication on the internet as in print.
“And it is not just the laws of your own country you need to worry about. When you post online you are posting to the whole world.”
It is important to remember that anything you post online can be viewed and even shared for the world to see.
Anyone with a Twitter account they use for work purposes will no doubt have been encouraged to add to their profile statement something along the lines of “views express are my own”.
While the website is all about sharing views and opinions, you do have to consider possible consequences of your tweeting.
Take the Department of Transport employee, for example, who had a disclaimer in her Twitter profile stating that the Tweets were personal opinions and were not representative of her employer.
But this didn’t stop The Independent newspaper from publishing her Tweets about her job, her feelings towards work and her views on government “spin” and Whitehall waste in an article about her employer.
She complained to the Press Complaints Commission, but they found that because Tweets are public property this was not an invasion of her privacy.