The complaints in this case were lodged prior to the UK legislating for a new surveillance regime, the 2016 Investigatory Powers Act, so in coming to a judgement the Chamber was considering the oversight regime at the time (and in the case of points 1 and 3 above that’s the Regulation of Investigatory Powers Act 2000).

RIPA has since been superseded by IPA but, as noted above, today’s ruling will likely fuel ongoing human rights challenges to the latter — which the government has already been ordered to amend by other courts on human rights grounds.

Nor is it the only UK surveillance legislation judged to fall foul on that front. A few years ago UK judges agreed with a similar legal challenge to emergency surveillance legislation that predates IPA — ruling in 2015 that DRIPA was unlawful under human rights law. A verdict the UK Court of Appeal agreed with, earlier this year.

Also in 2015 the intelligence agencies’ own oversight court, the IPT, also found multiple violations following challenges to aspects of its historical surveillance operations, after they have been made public by the Snowden revelations.

Such judgements did not stop the government pushing on with the IPA, though — and it went on to cement bulk collection at the core of its surveillance modus operandi at the end of 2016.

Among the most controversial elements of the IPA is a requirement that communications service providers collect and retain logs on the web activity of the digital services accessed by all users for 12 months; state power to require a company to remove encryption, or limit the rollout of end-to-end encryption on a future service; and state powers to hack devices, networks and services, including bulk hacking on foreign soil. It also allows the security agencies to maintain large databases of personal information on U.K. citizens, including individuals suspected of no crime.

On the safeguards front the government legislated for what it claimed was a “double lock” authorization process for interception warrants — which loops in the judiciary to signing off intercept warrants for the first time in the U.K., along with senior ministers. However this does not regulate the collection or accessing of web activity data that’s blanket-retained on all users.

In April this shiny new surveillance regime was also dealt a blow in UK courts — with judges ordering the government to amend the legislation to narrow how and why retained metadata could be accessed, giving ministers a deadline of November 1 to make the necessary changes.

In that case the judges also did not rule against bulk collection in general — declining to find that the state’s current data retention regime is unlawful on the grounds that it constituted “general and indiscriminate” retention of data. (For its part the government has always argued its bulk collection activities do not constitute blanket retention.)

And today’s ECHR ruling further focuses attention on the safeguards placed around bulk collection programs — having found the UK regime lacked sufficient monitoring to be lawful (but not that bulk collection itself is unlawful by default).

Opponents of the current surveillance regime will be busily parsing the ruling to find fresh fronts to attack.

It’s not the first time the ECHR has looked at bulk interception. Most recently, in June 2018, it deemed Swedish legislation and practice in the field of signals intelligence did not violate EU human rights law. Among its reasoning was that it found the Swedish system to have provided “adequate and sufficient guarantees against arbitrariness and the risk of abuse”.

However it said the Big Brother Watch and Others vs United Kingdom case being ruled upon today is the first case in which it specifically considered the extent of the interference with a person’s private life that could result from the interception and examination of communications data (as opposed to content).

In a Q&A about today’s judgement, the court notes that it “expressly recognised” the severity of threats facing states, and also how advancements in technology have “made it easier for terrorists and criminals to evade detection on the Internet”.

“It therefore held that States should enjoy a broad discretion in choosing how best to protect national security. Consequently, a State may operate a bulk interception regime if it considers that it is necessary in the interests of national security. That being said, the Court could not ignore the fact that surveillance regimes have the potential to be abused, with serious consequences for individual privacy. In order to minimise this risk, the Court has previously identified six minimum safeguards which all interception regimes must have,” it writes.

“The safeguards are that the national law must clearly indicate: the nature of offences which may give rise to an interception order; a definition of the categories of people liable to have their communications intercepted; a limit on the duration of interception; the procedure to be followed for examining, using and storing the data obtained; the precautions to be taken when communicating the data to other parties; and the circumstances in which intercepted data may or must be erased or destroyed.”

(Additional elements the court says it considered in an earlier surveillance case, Roman Zakharov v. Russia, also to determine whether legislation breached Article 8, included “arrangements for supervising the implementation of secret surveillance measures, any notification mechanisms and the remedies provided for by national law”.)

Commenting on today’s ruling in a statement, Megan Goulding, a lawyer for Liberty, said: “This is a major victory for the rights and freedom of people in the UK. It shows that there is — and should be — a limit to the extent that states can spy on their citizens.

“Police and intelligence agencies need covert surveillance powers to tackle the threats we face today — but the court has ruled that those threats do not justify spying on every citizen without adequate protections. Our government has built a surveillance regime more extreme than that of any other democratic nation, abandoning the very rights and freedoms terrorists want to attack. It can and must give us an effective, targeted system that protects our safety, data security and fundamental rights.”

A Liberty spokeswoman also told us it will continue its challenge to IPA in the UK High Court, adding: “We continue to believe that mass surveillance can never be compliant in a free, rights-respecting democracy.”

Also commenting in a statement, Silkie Carlo, director of Big Brother Watch, said: “This landmark judgment confirming that the UK’s mass spying breached fundamental rights vindicates Mr Snowden’s courageous whistleblowing and the tireless work of Big Brother Watch and others in our pursuit for justice.

“Under the guise of counter-terrorism, the UK has adopted the most authoritarian surveillance regime of any Western state, corroding democracy itself and the rights of the British public. This judgment is a vital step towards protecting millions of law-abiding citizens from unjustified intrusion. However, since the new Investigatory Powers Act arguably poses an ever greater threat to civil liberties, our work is far from over.”

A spokesperson for Privacy International told us it’s considering taking the case to the ECHR’s Grand Chamber.

Also commenting in a supporting statement, Antonia Byatt, director of English PEN, added: “This judgment confirms that the British government’s surveillance practices have violated not only our right to privacy, but our right to freedom of expression too. Excessive surveillance discourages whistle-blowing and discourages investigative journalism. The government must now take action to guarantee our freedom to write and to read freely online.”

We’ve reached out to the Home Office for comment from the UK government.

On intelligence sharing between governments, which the court had not previously considered, the judges found that the procedure for requesting either the interception or the conveyance of intercept material from foreign intelligence agencies to have been set out with “sufficient clarity in the domestic law and relevant code of practice”, noting: “In particular, material from foreign agencies could only be searched if all the requirements for searching material obtained by the UK security services were fulfilled.”

It also found “no evidence of any significant shortcomings in the application and operation of the regime, or indeed evidence of any abuse” — hence finding the intelligence sharing regime did not violate Article 8.

On the portion of the challenge concerning complaints that UK intelligence agencies’ oversight court, the IPT, lacked independence and impartiality, the court disagreed — finding that the tribunal had “extensive power to consider complaints concerning wrongful interference with communications, and those extensive powers had been employed in the applicants’ case to ensure the fairness of the proceedings”.

“Most notably, the IPT had access to open and closed material and it had appointed Counsel to the Tribunal to make submissions on behalf of the applicants in the closed proceedings,” it also writes.

In addition, it said it accepted the government’s argument that in order to ensure the efficacy of the secret surveillance regime restrictions on the applicants’ procedural rights had been “both necessary and proportionate and had not impaired the essence of their Article 6 rights”.