GCHQ's involvement in mass surveillance schemes run by the US National Security Agency (NSA) to gather data on millions of individuals was unlawful, the UK’s Investigatory Powers Tribunal (IPT) has ruled.
The decision is the first time in the IPT’s 15-year history that it has ruled against the government in its role as overseer of GCHQ, MI5 and MI6.
The case was brought by civil liberty groups including Amnesty International, Liberty and Privacy International in response to the Edward Snowden revelations of summer 2013.
The IPT ruling said that the activities undertaken by GCHQ were illegal as they breached European laws relating to Article 8, which refers to the right to respect for private and family life, and Article 10, which covers freedom of expression.
"... prior to the disclosures made and referred to in the First Judgment and the Second Judgment, the regime governing the soliciting, receiving, storing and transmitting by UK authorities of private communications of individuals located in the UK, which have been obtained by US authorities pursuant to Prism and/or (on the Claimants’ case) Upstream, contravened Articles 8 or 10 ECHR".
The document then states that the regime "now complies with the said Articles".
This is because GCHQ has made public two additional paragraphs of information outlining how it collects and data it collects public under the Regulation of Investigatory Powers Act.
A GCHQ spokesperson said the decision was proof the oversights in place are effective.
“Today’s IPT ruling re-affirms that the processes and safeguards within the intelligence-sharing regime were fully adequate at all times - it is simply about the amount of detail about those processes and safeguards that needed to be in the public domain," they said.
“By its nature, much of GCHQ’s work must remain secret. But we are working with the rest of government to improve public understanding about what we do and the strong legal and policy framework that underpins all our work."
However, Eric King, deputy director of Privacy International, said that the ruling was a major blow against GCHQ and its activities and vindicated the efforts of Edward Snowden to reveal the extent of surveillance taking place.
"For far too long, intelligence agencies like GCHQ and the NSA have acted like they are above the law," he said.
"Today’s decision confirms to the public what many have said all along. Over the past decade, GCHQ and the NSA have been engaged in an illegal mass surveillance sharing programme that has affected millions of people around the world."
King added that "the world owes Edward Snowden a great debt for blowing the whistle, and today's decision is a vindication of his actions", and that efforts to keep the authorities in check must continue.
"We must not allow agencies to continue justifying mass surveillance programmes using secret interpretations of secret laws," he said.
James Welch, legal director for Liberty, also welcomed the ruling. “We now know that, by keeping the public in the dark about its secret dealings with the NSA, GCHQ acted unlawfully and violated our rights,” he said.
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