The mood toughened just over a month ago, when I received a phone call from the centre of government telling me: "You've had your fun. Now we want the stuff back." There followed further meetings with shadowy Whitehall figures. The demand was the same: hand the Snowden material back or destroy it. I explained that we could not research and report on this subject if we complied with this request. The man from Whitehall looked mystified. "You've had your debate. There's no need to write any more."
During one of these meetings I asked directly whether the government would move to close down the Guardian's reporting through a legal route - by going to court to force the surrender of the material on which we were working. The official confirmed that, in the absence of handover or destruction, this was indeed the government's intention.
The newspaper told the government that even if they did comply, it would be pointless - all the materials related to Snowden had already been spread throughout the world, the actual editing was done in New York, the journalist in question (Greenwald) lived in Brazil - but the British government stood fast.
And so one of the more bizarre moments in the Guardian's long history occurred - with two GCHQ security experts overseeing the destruction of hard drives in the Guardian's basement just to make sure there was nothing in the mangled bits of metal which could possibly be of any interest to passing Chinese agents. "We can call off the black helicopters," joked one as we swept up the remains of a MacBook Pro.