Britain's GCHQ violated human rights by accessing intelligence from the NSA's mass surveillance programs, a UK court ruled today, though the agency is now considered compliant after disclosing details of the arrangement late last year. In a ruling handed down Friday morning, the Investigatory Powers Tribunal (IPT) said the GCHQ, Britain's NSA-equivalent, violated rights to privacy and free speech under an intelligence sharing arrangement that allowed it to access data from the NSA's PRISM and upstream surveillance programs.

The IPT is the only court with the authority to oversee the GCHQ and Britain's other intelligence services. This marks the first time in its 15-year history that the tribunal has ruled against an intelligence and security agency.

A mixed result for privacy advocates

The ruling follows a December 2014 decision in which the IPT said that the GCHQ's bulk data collection programs were in accordance with the law. But details of the intelligence sharing arrangement between the NSA and GCHQ weren't made public until the December hearings. In today's ruling, the tribunal determined that the agency violated European human rights law by not disclosing those details prior to December 2014, though now that they're public, the program is in full accordance with the law.

"We are pleased that the Court has once again ruled that the UK’s bulk interception regime is fully lawful," a GCHQ spokesperson said in an email statement. "It follows the Court’s clear rejection of accusations of ‘mass surveillance’ in their December judgment."

The GCHQ's surveillance programs were challenged by Amnesty International, Privacy International, and other rights groups.

More challenges are on the way

"For far too long, intelligence agencies like GCHQ and NSA have acted like they are above the law," Eric King, deputy director of London-based Privacy International, said in an email statement. "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 program that has affected millions of people around the world."

But the rights groups remain dissatisfied with the court's decision that the disclosure of certain safeguards is sufficient to consider it legal. They say they will challenge the December decision in the European Court for Human Rights.

"[T]he Intelligence Services retain a largely unfettered power to rifle through millions of people’s private communications – and the Tribunal believes the limited safeguards revealed during last year’s legal proceedings are an adequate protection of our privacy," said James Welch, legal director for the rights organization Liberty, which was among the groups filing the initial complaint. "We disagree, and will be taking our fight to the European Court of Human Rights."