Who needs the movies when life is full of such spectacular coincidences? On Thursday, David Anderson, the government’s reviewer of terrorism legislation, condemned snooping laws as “undemocratic, unnecessary and – in the long run – intolerable”, and called for a comprehensive new law incorporating judicial warrants – something for which my organisation, Liberty, has campaigned for many years. This thoughtful intervention brought new hope to us and others, for the rebuilding of public trust in surveillance conducted with respect for privacy, democracy and the law. And it was only possible thanks to Edward Snowden. Rumblings from No 10 immediately betrayed they were less than happy with many of Anderson’s recommendations – particularly his call for judicial oversight. And three days later, the empire strikes back! An exclusive story in the Sunday Times saying that MI6 “is believed” to have pulled out spies because Russia and China decoded Snowden’s files. The NSA whistleblower is now a man with “blood on his hands” according to one anonymous “senior Home Office official”.

Low on facts, high on assertions, this flimsy but impeccably timed story gives us a clear idea of where government spin will go in the coming weeks. It uses scare tactics to steer the debate away from Anderson’s considered recommendations – and starts setting the stage for the home secretary’s new investigatory powers bill. In his report, Anderson clearly states no operational case had yet been made for the snooper’s charter. So it is easy to see why the government isn’t keen on people paying too close attention to it.

But then, when it comes to responding to criticism, the approach of the Conservative leadership has been the same for some time: shut down all debate by branding Snowden – or anyone else who dares question the security agencies – as an enemy of the state and an apologist for terror.

It’s a technique we at Liberty have felt the full force of. In March, the discredited, and now largely retired, intelligence and security committee produced a report into the legal framework covering surveillance. This was the same toothless committee that failed to spot the dodgy dossier, expose extraordinary rendition or pick up on the sheer scale of blanket intrusion outside of the law – which Snowden did a great public service in revealing.

Instead of properly scrutinising the agencies’ activities, the ISC lashed out against campaigners, shamelessly misrepresenting us as considering terrorism a price worth paying for our airy-fairy values. Valid concerns of campaigners and parliamentarians were buried under a mound of toxic spin.

The hyperbole that followed yesterday’s story was astonishing – Professor Anthony Glees reportedly branded Snowden “a villain of the first order” – Darth Vader eat your heart out.

So let me be completely clear: Edward Snowden is a hero. Saying so does not make me an apologist for terror – it makes me a firm believer in democracy and the rule of law. Whether you are with or against Liberty in the debate about proportionate surveillance, Anderson must be right to say that the people and our representatives should know about capabilities and practices built and conducted in our name.

For years, UK and US governments broke the law. For years, they hid the sheer scale of their spying practices not just from the British public, but from parliament. Without Snowden – and the legal challenges by Liberty and other campaigners that followed – we wouldn’t have a clue what they were up to.

A debate about surveillance powers in the internet age is not best advanced by that all-pervading slogan: “nothing to hide, nothing to fear.” We cannot have a risk-free society, and it is too much to expect of the agencies or the law to deliver it. But surely we can have an open and balanced discussion about how we adapt to new threats while safeguarding the intimacy and dignity rightly craved by human beings.