Websites using Facebook's 'Like' button liable for data: EU court

" The operator of a website that features a Facebook ‘Like' button can be a controller jointly with Facebook in respect of the collection and transmission to Facebook of the personal data of visitors to its website," said the Court of Justice of European Union (ECJ) in its ruling.

The Luxembourg-based court looked into the case of "Fashion ID", a German online clothing retailer, which embedded on its website the Facebook ‘Like' button.

The consequence of embedding that button appears to be that when a visitor consults the website of Fashion ID, that visitor's personal data are transmitted to Facebook Ireland.

"It seems that that transmission occurs without that visitor being aware of it and regardless of whether or not he or she is a member of the social network Facebook or has clicked on the ‘Like' button," said the ruling.

A German public-service association tasked with safeguarding the interests of consumers criticised "Fashion ID" for transmitting to Facebook Ireland personal data of visitors to its website, first, without their consent and, second, in breach of the duties to inform set out in the provisions relating to the protection of personal data.

The court held that "Fashion ID" cannot be considered to be a controller in respect of the operations involving data processing carried out by Facebook Ireland after those data have been transmitted to the latter.

"It seems, at the outset, impossible that Fashion ID determines the purposes and means of those operations. By contrast, Fashion ID can be considered to be a controller jointly with Facebook Ireland in respect of the operations involving the collection and disclosure by transmission to Facebook Ireland of the data at issue," read the judgment.

Fashion ID's embedding of the Facebook ‘Like' button on its website allows it to optimise the publicity for its goods by making them more visible on the Facebook social network when a visitor to its website clicks on that button.

Facebook said in a statement that "We are carefully reviewing the court's decision and will work closely with our partners to ensure they can continue to benefit from our social plugins and other business tools in full compliance with the law," reports CNET.