Internet users should boycott "vile" websites which allow cyberbullying to avoid more deaths of young people who receive abuse online, the Prime Minister has said.
David Cameron said website operators must "step up to the plate" to ensure people are protected from online abuse following the death of 14-year-old Hannah Smith, who was found hanged on Friday after being bullied on ask.fm.
Her father David Smith said those who run the website should face murder or manslaughter charges and called for more regulation of social networking sites.
Speaking during a visit to a hospital in Salford, Mr Cameron told Sky News: "The people that operate these websites have got to step up to the plate and show some responsibility in the way that they run these websites.
"Second point is, just because someone does something online, it doesn't mean they're above the law. If you incite someone to do harm, if you incite violence, that is breaking the law, whether that is online or offline.
"Also there's something all of us can do as parents and as users of the internet and that is not to use some of these vile sites. Boycott them, don't go there, don't join them - we need to do that as well.
"I'm very keen we look at all the action we can take to try and stop future tragedies like this."