A British teenager charged with hacking offences and believed to be a leading member of the Anonymous and LulzSec online activist groups was released on bail in a London court on condition he did not use the internet.

Jake Davis, 18, who goes by the online nickname of "Topiary", was charged with computer attacks on Sony, UK crime and health authorities and Rupert Murdoch's UK newspaper arm News International.

Jake Davis, left, leaves Westminster Magistrates Court in London, England.

Anonymous and LulzSec members have been arrested in the United States, Spain, Turkey, Britain and the Netherlands in recent weeks in a crackdown on attacks on targets seen by the activists as hostile to internet freedom of speech.

The arrest of "Topiary" in Scotland's remote Shetland Islands may be the most significant to date in the global effort to end the cybercrime spree by the groups.