An embittered attack on an ex-friend cost a Facebook user £22,000 this week in libel damages at the high court, in what is sure to be seen as a landmark ruling.

After Grant Raphael fell out with his ex-business partner and former school friend Mathew Firsht he decided that it would be a good idea to create fake allegations about Firsht's sexual preferences and political allegiances on Facebook.

This 'good idea' backfired and has now cost Raphael £22,000.

Lies, damned lies and Facebook

In addition to besmirching his personal reputation, Raphael also created a company profile called "Has Mathew Firsht lied to you?" on Facebook.

Firsht has now successfully sued Raphael for libel and misuse of private information, in what is sure to be seen as a landmark case for the misuse of private information on social networking sites.

Deputy Judge Richard Parkes QC awarded Firsht £15,000 for libel, £2,000 for breach of privacy and Firsht's company was awarded £5,000 for libel.

Be careful what you post

Jo Sanders, media lawyer at law firm Harbottle & Lewis, said: "The significance of this case is that it shows that what you post is not harmless, but has consequences.

"Sat at home or school or in the office, it's easy to think of social networking sites as harmless fun, that it's like chatting with friends, and that things posted there are either a joke or just a mischievous way of causing embarrassment. This ruling puts an end to that."

Facebook said in a statement: "Facebook does not permit fake profiles on its site. Fake profiles are an abuse of our terms of use and they will be removed.

"When fake profiles are reported we thoroughly investigate and remove profiles found to be in violations of our terms of use - just as we did in the case of Mathew Firscht [sic]."