British authorities knew that perfectly well. He was the partner of a journalist. They suspected he was in fact carrying copies of Edward Snowden's NSA and GCHQ files, which Greenwald was engaged in researching and publishing. Their prime purpose, as they were later to admit, was simply to get hold of the files, and find out how much Greenwald knew.

The two police officers who rifled through Miranda's backpack and questioned him in a custody suite asked virtually nothing about terrorism. They didn't inquire if Miranda was a member of a terrorist group. Miranda says the questions he was asked "seemed random and unfocused ... They gave me the impression that they were questioning me just to give themselves time to examine the material."

Documents obtained in the subsequent legalroutine as possible, and that it appears that this stop is not at the request of the Security Service."

The use of schedule 7 against someone who was known not to be a terrorist was a blatant abuse – and an alarming precedent in which a government matched journalism with terrorism.

This was the first time the much-criticised section of the act had been used against a journalist carrying source material. Coming on top of the forced destruction of the Guardian's computers on 20 July, it looked like a chilling attack on press freedom.