British spies did not break laws guaranteeing human rights when they used mass monitoring techniques revealed by former U.S. National Security Agency contractor Edward Snowden, the country's surveillance watchdog ruled on Friday.
A host of civil rights groups and privacy campaigners, including Amnesty International and the American Civil Liberties Union, had argued the tactics used by Britain's three security agencies and disclosed by Snowden to the media last year did not comply with the UK's Human Rights Act.
"The 'Snowden revelations' in particular have led to the impression voiced in some quarters that the law in some way permits the Intelligence Services carte blanche to do what they will. We are satisfied that this is not the case," Britain's Investigatory Powers Tribunal (IPT) said in its ruling.
Snowden caused an international uproar when he disclosed details of the extent of surveillance and electronic monitoring by the NSA and its British equivalent, the General Communications Headquarters, or GCQA.
He told newspapers the NSA was mining the personal data of users of Google, Facebook, Skype and other U.S. companies under a secret program codenamed Prism, while GCHQ was accused of bypassing British laws by gaining access to communications without proper authority.
GCHQ was also accused of tapping fibre-optic cables that carry international phone and internet traffic and sharing the data with the United States.
"We have ruled that the current regime, both in relation to Prism and Upstream (another NSA program) when conducted in accordance with the requirements which we have considered, is lawful and human rights-compliant," the IPT said.
Rachel Logan, legal adviser for Amnesty UK, said the decision would be appealed to the European Court of Human Rights.
"The government has managed to bluff their way out of this, retreating into closed hearings and constantly playing the 'national security' card," she said.
"The government's entire defense has amounted to 'trust us' and now the tribunal has said the same. Since we only know about the scale of such surveillance thanks to Snowden, and given that 'national security' has been recklessly bandied around, 'trust us' isn't enough."
The new head of GCHQ said last month the security services needed greater access to Facebook and Twitter because of their importance to militant groups, while spy chiefs have argued Snowden's revelations have damaged their capabilities and put operations at risk.