Last year, despite the shadow of the Snowden revelations looming large, the Coalition Government opted to pave the way for yet more unchecked surveillance, by rushing so-called "emergency" legislation into law inside a matter of days.
That law - the Data Retention and Investigatory Powers Act ("DRIPA", for short) - allows the home secretary to require the retention of all our communications data - who we e-mail, call or text, the websites we visit and where we are when we use our smartphones. Such data is then subject to an extremely lax access regime, allowing it be acquired by hundreds of public authorities - all but local authorities free to grant access themselves, for reasons wholly unrelated to investigating serious crime.
Not only did ministers ignore an EU Court of Justice judgment, delivered in April 2014 (three months before DRIPA emerged - so perhaps not such an "emergency" after all), which ruled that blanket retention of private data breached human rights. But the way in which it was railroaded onto the statute book - after a private stitch-up between the then three main party leaders - made proper scrutiny, amendment and even debate in Parliament impossible.
Neither we - nor two MPs from opposing sides of the chamber, David Davis and Tom Watson - were prepared to let such an abuse of power go unchecked. So we launched a legal case, arguing that DRIPA was unlawful.
Today - exactly one year after the legislation received Royal Assent - the High Court has agreed.
Judges ruled that sections 1 and 2 of DRIPA are incompatible with the British public's right to respect for private life and communications and right to protection of personal data, under Articles 7 and 8 of the EU Charter of Fundamental Rights. That's because the law does not ensure private communications are accessed only for fighting serious crime - and because access to such data is not authorised by the Courts.
These unlawful sections will remain in force for now - to allow time for the Government to get its house in order, and legislate properly - before expiring in March 2016. The Government gave Parliament just days to consider its botched surveillance law - the Court has allowed almost nine months.
Today's is a landmark victory. At Liberty we've long called for reform of our surveillance laws to make sure the public's rights are properly respected by our Government. Now we see the consensus of voices, demanding change on surveillance, continuing to grow. The High Court has joined campaigners, journalists, MPs across the political spectrum, the Government's own reviewer of terrorism legislation, former intelligence chiefs, and many more - all of whom are calling for judges to sign off on surveillance requests.
In response, the Government will no doubt make lots of noise about terrorism and keeping us all safe. But - to be crystal clear - we take no issue with surveillance powers. Nor do we dispute the importance of targeted surveillance by the security services and law enforcement agencies to prevent and detect serious crime.
But intrusive surveillance is justifiable only when it's in accordance with the law and both necessary and proportionate. Unfortunately, the current self-authorisation regime just does not provide sufficient safeguards.
In some of the rare instances in which spying has come to light in recent years, this inadequacy of the existing system has been laid bare. The Metropolitan Police has been free to access journalists' private phone records, spy on grieving mother Doreen Lawrence and her family, and infiltrate social and environmental justice groups to the extent that women were deceived into romantic relationships - one even having a child with an undercover officer. Meanwhile, legal challenges have revealed that GCHQ has intercepted legally privileged communications of a torture victim, and spied on respected human rights groups.
Despite such disclosures, the home secretary, Theresa May, has so far refused to heed the increasing recommendations for prior judicial approval of surveillance requests. In so doing, she is fighting a rather solitary battle. Indeed, the UK is the only of the "Five Eyes" nations - an intelligence alliance comprising ourselves, the US, Australia, Canada, and New Zealand - which makes no use of judges in the prior authorisation of interception warrants.
Today's ruling should surely convince her that it's now time for the Government to commit to surveillance conducted with respect for privacy, democracy and the rule of law - rather than stubbornly ploughing ahead with more of the same.