Since becoming the US President, Donald Trump has been widely criticised for his Twitter use. One example was his retweet of an image which showed crime statistics categorised by race. Subsequently, it was discovered that the numbers were inaccurate and had come from a source which did not in fact exist. In his defence, Trump said: "I retweeted somebody that was supposedly an expert."

In the US, freedom of expression will in most cases overcome the right to protect one's good name but this is not the case in Europe where reputation and privacy rights receive equal consideration.

Last month, a court in Switzerland decided that by liking defamatory statements on Facebook, the user had adopted those statements as his own and disseminated them further making them accessible to a multitude of people.

In contrast to the law on defamation in Ireland, in Switzerland defamation is treated as a crime rather than a civil wrong. By liking defamatory statements which included content contrary to the interests of the animal rights activist Erwin Kessler and his animal rights group, the court decided that the accused had adopted those statements as his own and had disseminated them.

The Facebook posts which had been liked included references to Erwin Kessler as an anti-Semite, a racist and a fascist. The accused was unable to prove that these statements were true and neither could he show grounds for an honest belief in the truth of the statements. His defence therefore failed.

Not only did the court find that the liking of a Facebook post by a third party amounts to an endorsement and an adoption of that statement as one's own, the court also found that liking a Facebook post is an act of dissemination - ie the onward distribution or publication of content.

Given this recent decision and the possibly wide-ranging implications of it, it is necessary to consider the approach in other jurisdictions on this topic. In 2013 a court in Hamburg also looked at the meaning of a Facebook like in the context of legal liability. The case did not involve defamation but related to an allegation of deceptive advertising, where users could enter a competition to win prizes by liking a Facebook page and by fulfilling certain other criteria.

It was argued here that the defendant was buying positive feedback and that other users, unaware of the competition, might consider the boost in likes as an endorsement of the company's products.

In this case liking a post or page on Facebook was equated by the court with a non-binding expression or neutral act. The court reasoned that in order for the like to be considered an endorsement, it should be accompanied by a comment or post in writing. So, in the absence of additional information, the motive for clicking 'like' effectively remains hidden and neither carries a positive nor a negative meaning. Arguably, this reasoning could be applied to a case in defamation.

In the UK, the widely publicised defamation action by Lord McAlpine, former conservative politician, against Sally Bercow, wife of John Bercow (Speaker of the House of Commons), highlights the dangers of tweeting and retweeting content. This case arose following the broadcast of a BBC Newsnight programme in November 2012 concerning an investigation into the abuse of boys at a children's home in Wales by a leading conservative politician.

The politician was not named but prominent tweeters, including Ms Bercow, inferred that McAlpine was the politician concerned. The rumour that it was McAlpine was later acknowledged by numerous newspapers, broadcasters and the accuser to be completely untrue.

Sally Bercow's tweet did not expressly link the BBC Newsnight broadcast with McAlpine but instead tweeted: "Why is Lord McAlpine trending? *innocent face*". Defamation proceedings were issued with the UK Courts holding as a preliminary finding that the meaning of the tweet and in particular the words "innocent face" was that Lord McAlpine was a paedophile who was guilty of sexually abusing boys living in care and therefore, was defamatory. It was also argued during the case that it was foreseeable that a substantial number of Bercow's followers (she had more than 56,000 at the time) would retweet the message.

Interestingly, a retweet sent by Alan Davies, comedian and actor, naming McAlpine as connected with the allegations also became the subject of defamation proceedings. Following the settlement of that action, Mr Davies issued a statement through his lawyers warning of the dangers of retweeting.

In Ireland, an act of defamation arises if a defamatory statement concerning a person or company is published to at least one other person. Of course, the Defamation Act 2009 was not drafted to deal with the scenario of liking or retweeting potentially defamatory content. However, at its simplest, the law is designed to stop the spread of false rumour and if you take it that repeating a defamatory allegation without saying you agree or endorse the allegation is publication, then if you like a defamatory post or retweet a defamatory tweet, you could be faced with legal action.

Under Irish law, defences could include either establishing the truth of the content or establishing that you honestly held the opinion contained in the published statement. The recent examples in Switzerland and the UK, the Kessler and McAlpine cases, show that users who retweet or like content, if pursued, will invariably fail to defend these actions. This is possibly because the users have simply engaged with content without knowing the facts behind the statements and are therefore not in a position to defend their actions. Defamation law in Ireland and in other jurisdictions is constantly evolving. Legal risks continue to emerge in this area and the Kessler and McAlpine cases are cautionary tales to all social media users to take stock, pause and consider the truth or otherwise of content before sharing, liking or retweeting.

Indo Business