BBC current affairs shows have long been about their own adversarial tone, and there's something to be thankful in that: Britain's media culture forces politicians to subject themselves to grillings in a way that just doesn't happen much in America. But the fearless, no-nonsense style is often so affected that it relies upon the anxiety and obedience of interview subjects. When one comes along who knows what the deal is, the hosts are left to "yes, but" their way through trivial and poorly-prepared interview scripts.

A perfect example unfolded on BBC Newsnight yesterday, where The Guardian's Glenn Greenwald faced off against an interviewer, Kirsty Wark, so hopeless that she didn't even know the good questions to attack him with.