Police investigating 'hacktivist' collectives Anonymous and LulzSec have issued a statement warning the groups they risk a 10-year prison sentence.
The comments come after the alleged leader of LulzSec, Jake Davis, who goes by the name Topiary online, was arrested in the Shetland Islands for allegedly hijacking the website of the Sun newspaper.
However hacking groups remained defiant over their actions following his detention, with Anonymous warning that police were arresting “protesting citizens” and they would continue with their activities.
"We will never rest as we are Legion. Arrest more of us. We dare you. With every day that passes, we store more of your secrets," the group wrote on Twitter.
The two online activists groups have claimed responsibility for computer attacks such as hacking into the computers of Sony, Nato, the CIA and the UK police’s Serious Organised Crime Agency website.
In a statement, police said: “Under UK legislation, it is an offence if a person acts from within the UK upon a computer anywhere else in the world. It is also an offence if someone anywhere else in the world to criminally affect a computer within the UK."
They added: "Anyone considering accessing a computer without authority should understand that such acts are unlawful and can carry a term of imprisonment."
Davis was arrested on July 27 and has been charged with five offences. He has been released on bail.