The European Court of Human rights in Strasbourg has set a dangerous legal precedent threatening freedom of speech and online publishing. In particular, a ruling issued this week says that Estonian news site Delfi may be held liable for anonymous and allegedly defamatory comments that readers post on its site.

The case relates to a 2006 article published by Delfi about SLK, a local ferry company. Even though the article itself was considered balanced and fair, there were many offensive or threatening anonymous comments about the ferry operator and its owner. However, according to the court, allowing anonymous comments stems from a commercial decision on Delfi's part – attracting more people to voice their opinions – and therefore it should be held liable.

This despite the fact that the publisher's commenting system allowed users to flag and automatically hide posts that they found offensive. According to reports, it also segregated anonymous comments from those of registered users, hiding them by default on its site, and the offensive comments had been removed following the initial complaint, prior to the lawsuit being filed.

In the U.S., the Communications Decency Act (CDA) specifically says that websites aren't liable for the comments and content that users post online. Website owners are merely treated as a service provider.

According to EFF, under the E-commerce Directive in Europe (the region's equivalent to DMCA takedowns), Delfi would normally be exempted from liability for user content unless it refuses to remove it after being informed of its illegality. But there's a loophole in this directive as it provides a minimum level of intermediary liability without defining the limits of liability.

The court points out in its ruling that it doesn't apply to other sites like forums or social networks but it's a worrying precedent that could prompt websites to enforce real-name registration policies, undermining anonymity, or eliminate posting altogether when they can't afford to implement screening procedures.