EU – Baltic States, Internet, Latvia, Legislation, Technology

Hannah Smith, 14, hanged herself last week. Friends said she had been taunted on "ask.fm" about everything from her weight to the death of her uncle. Bullies bombarded her with anonymous messages, telling her to "drink bleach" and "go die".

Campaigners say she is not the first teenager to be "bullied to death" on "ask.fm", which counts millions of adolescents around the globe amongst its 60 million registered users.

The website - which has turned its founders, brothers Mark and Ilja Terebin, into millionaires since it launched in 2010 - has been linked to at least four other teen suicides in Britain, Ireland and the US this year.

Hannah's death has pushed criticism of the website to fever pitch, with parents - including Prime Minister David Cameron - asking why users are able to post such vicious remarks with complete anonymity, often to youngsters in the same school class.

Wary of the negative publicity, advertisers including telecoms giant "Vodafone" and designer Laura Ashley have scrambled to abandon the site - and after Cameron called Thursday for users to boycott it, "ask.fm's" founders were forced to issue a defense.

"We are committed to ensuring that our site is a safe environment," the Terebin brothers insisted in a statement. "We do not condone bullying of any kind."

The website had already described Hannah's suicide as a "true tragedy" and said it is working with police investigating the death.

Her father has called for its operators to face murder or manslaughter charges.