The Q&A was streamed live on Amnesty International's YouTube channel from its east London headquarters on Tuesday, June 2, to mark two years since the “Snowden revelations”.

In June 2013 the former NSA contractor disclosed information about mass surveillance practices carried out by USA National Security Agency - which had a profound effect on how we think about the technology we use.

ALSO ONLINE: Newham is most deprived borough in the country

The live-link Q&A will be followed by a screening of Citizenfour, the Oscar-winning feature documentary by Laura Poitras which follows Snowden, code-named ‘Citizenfour’ as he reveals to Guardian journalist Glenn Greenwald the mass surveillance information that shocked the world.