In this modern world filled with the variable multitudes of social media from Facebook, to Twitter, to LinkedIn, or YouTube, to name just the heavy weights, it is very easy to post, tweet or share something without thinking about the possible legal repercussions. It seems like almost everyday an incriminating tweet leads someone into trouble with the law. Whether it be a law student tweeting racist comments to a footballer fighting for his life after a heart attack, or a trainee accountant knocking a cyclist off the road and tweeting #bloodycyclists, or the Commons Speaker’s wife tweeting libellous comments regarding a Tory peer. Or most recently eleven members of the public being arrested nationwide for making ‘racist or anti-religious’ comments on Facebook and Twitter following the death of Lee Rigby.

But what about tweets or posts that may inadvertently result in a binding contract being made between parties? A quick search of social media and you will quickly find tweets and posts asking for something and promising something in return. If you RT this I will…” or “Like this and we will…” etc. Often these are made by companies for products or services. But is it possible that posts by the average tweeter, perhaps even said in jest, might form a binding contract between themselves and the people who follow them?

Any first year law student will know the case of Carlill v Carbolic Smoke Ball Company [1892] EWCA Civ 1. The Carbolic Smoke Ball Company produced the “smoke ball” which they claimed to be a cure for influenza as well as a number of ailments including hay fever. The Company published advertisements claiming that it would pay £100 to anyone who got sick with influenza even after using its’ product in accordance with the instructions set out in the advertisement:


£100 reward will be paid by the Carbolic Smoke Ball Company to any person who contracts the increasing epidemic influenza colds, or any disease caused by taking cold, after having used the ball three times daily for two weeks, according to the printed directions supplied with each ball.  £1,000 is deposited with the Alliance Bank, Regent Street, showing our sincerity in the matter.

Mrs Carlill saw the advertisement, bought one of the smoke balls and used it three times a day for nearly two months until she contracted influenza in January 1892. She subsequently went on to claim the £100 from the Carbolic Smoke Ball Company. The Company went on to ignore two letters sent by Mr Carlill, the claimant’s husband and a solicitor, and on a third request for the £100 reward, the Company replied with an anonymous letter that they had complete confidence in their product’s efficacy if used properly, however in order “to protect themselves against all fraudulent claims” they would require the claimant to attend their offices and to use the smoke ball each day while being checked by one of their secretaries.

Mrs Carlill brought her claim to the court arguing that the advertisement by the defendant and her reliance upon it was a binding contract between herself and the company, a contract that the defendant had breached by not paying her the £100. The Carbolic Smoke Ball Company argued that it was not a serious contract and should not have been relied upon by the claimant.

The court held that the contract was not between the Carbolic Smoke Ball Company and the whole world, but rather only with those who fulfilled the stipulated conditions of the offer made by the defendant. The terms were not vague if read in their plain meaning. However if someone used the smoke ball before the advertisement and subsequently got the flu then there would be no contract created due to no reliance interest. As for defendant’s argument that it should not have been taken seriously, the court noted that the advertisement indicated that they had placed £1,000 into a bank which directly contradicted their defence. Furthermore, performance of the condition of the advertisement was adjudged to be sufficient acceptance and it was therefore not necessary that Carbolic Smoke Ball Company be notified by the claimant of their intention to be bound by the contract. The court further ruled that the inconvenience of Carlill was sufficient consideration.

Yes, Carbolic Smoke Ball Co is a more than a hundred year old case and the judges that decided it unlikely had any idea that social media could or would one day exist but there is no reason why the basic principles of contract law i.e. offer, acceptance, and consideration would not make social media the same as any other written medium.

Indeed it is now perfectly acceptable for one party to serve legal documents upon another through the medium of Facebook especially in circumstances where there is a difficulty in locating one of the parties such as here. Facebook has routinely been used to serve claims in Australia and New Zealand, and has now been used a handful of times in the UK. While in 2009, Mr Justice Lewison allowed an injunction to be served via Twitter in a case where the defendant was only known by his Twitter-handle and could not easily be identified in any other way. More proof, if any were needed, that the law and the courts are willing to embrace social media and its’ importance to modern culture as any other medium.

So the next time you think of posting something like the tweet below maybe perhaps you should think again, just in case your tweet comes back to peck you on the @rse.


Disclaimer: The views expressed are those of the writer and this article does not constitute legal advice. the writer makes no comment on the liability owed by the owner of the above mentioned tweet towards those that have retweeted him…all 4,066 of them.