Edward Snowden says he plans to develop and promote anti-surveillance technology to hamper government spying across the globe. The former US National Security Agency contractor, who leaked confidential documents detailing the extensive surveillance activities of the NSA and the UK’s GCHQ, called for support at the Hackers On Planet Earth conference via a video link from Moscow, Russia. Snowden addressed the conference on Saturday, requesting that the hacking community channel its resources into developing anti-surveillance technologies which will making government spying more difficult, and said that he planned to spend much of his future time doing the same.