Edward Snowden warns over Google and Facebook's 'dangerous services'

Web giants paving the way for NSA, and GCHQ - who Snowden accuses of running a domestic surveillance programme in which 'anything goes'

US National Security Agency (NSA) whistleblower Edward Snowden has warned that web giants Google and Facebook are compromising people's privacy, describing them as "dangerous services". He also slammed Dropbox and urged people to remove the web app from their computers.

Dropbox, said Snowden, held people's data on their behalf, encrypted and kept the key - and would willingly hand it over to any government that asked.

He also claimed that authorities in the UK operate a surveillance systems without controls where "anything goes", operating a monitoring system even more intrusive than in the US without justification.

"The UK ... [has a] the system of regulation where anything goes. They collect everything that might be interesting. It's up to the government to justify why it needs this. It's not up to you to justify why it doesn't...

"This is where the danger is, when we think about... evidence being gathered against us, but we don't have the opportunity to challenge that in courts. It undermines the entire system of justice," he told the Observer newspaper.

Snowden was appearing at the Observer Ideas festival via a Skype and Google Hangout link - an irony he acknowledged. "I'm about to disconnect this machine and toss it into a fire," he joked.