Last June, Edward Snowden, a man still in his twenties with, as he put it, "a home in paradise", went on the run. He took with him vast amounts of secret information belonging to the US government's security services.
Snowden holds libertarian - or anti-statist - views. He believes the American government's pervasive surveillance activities which he revealed break the law but are also morally wrong.
In Britain, "The Guardian" newspaper published the classified information Snowden had obtained. This seemed odd. Editorially, it was not sympathetic to Snowden's anti-state nostrums. But, on privacy grounds, it agreed with him that it was inherently wrong for democratic governments to spy on their citizens online. Furthermore, it argued that governments should not decide for themselves when and how they would do their surveillance.
It is this political alliance between the libertarian right and the liberal left - which are normally opposed to one another - which David Aaronovitch investigates in this programme.
He explores, in a detailed interview with the editor of "The Guardian", Alan Rusbridger, why the newspaper published the secret information. Are states threatening citizens' privacy in the cyber age? Or is it in fact governments which are more vulnerable than ever before to the unauthorised disclosure of their secrets?
What secrets is the state itself entitled to keep from its citizens and from potential enemies? And who decides that question?the security services, Parliament or the government? Or the press and the whistle-blowers? Alan Rusbridger claims his newspaper can properly adjudicate what should and should not be published about state secrets. But how does he justify that apparently self-serving argument?