Matt Damon as Jason Bourne: Killing machine who became a target 

A year after the 9/11 atrocities, I made a documentary for Channel 4 which involved trying to discover what had happened to terrorist suspects the prison service was holding without charge. The director filmed me putting questions to a low-level functionary at the Home Office press office. We hoped he would stonewall and thus unwittingly illustrate a sequence about Whitehall secrecy. Fortunately for us, he obfuscated like a true PR. Channel 4 wanted a witty line in the commentary to emphasise how hard it was to extract information that should be freely available. The best I could manage was "It's easier to have a beer with Osama bin Laden than get this government to answer a question." I accept that I was never going to get the viewers rolling off their sofas and clutching their aching sides, but the commissioning editor's response took me aback. Absolutely not. Cut it out. It's offensive.

But we were at war with al-Qaeda, I protested. Osama bin Laden is the enemy of this country and its best values. Why should I worry about offending him? He was equally taken aback by my insubordination. Like the Home Office press office, he did not think he had to answer presumptuous questions from journalists. After spending years watching the London media class at work and play, I guessed that three emotions were whirring round in his mind:

1) Fear. Ever since the Rushdie affair, British editors have feared that criticism of radical Islamists will lead to attacks on their staff and, more pertinently, on themselves. Suppressed panic explains why British newspapers did not follow European and indeed Middle Eastern newspapers in running the Danish cartoons of Muhammad. Although it is absurd to believe that a weak joke about bin Laden would provoke jihadis into bombing Channel 4's glass and steel headquarters in Westminster, cowards die many times before their deaths and once cowed editors have killed one story, they will kill hundreds more.

2) Racism. Although few television executives say so explicitly, most believe that the bulk of British Muslims support al-Qaeda in an inchoate way. Offending the enemy therefore means offending multiculturalism. If the accusation of "Islamophobia" carries any meaning, it must condemn the assumption that all Muslims are terrorist sympathisers. Although they say they don't accept the calumny in theory, most in television behave as if they do in practice.

3) Conformism. Once small bands of people have established a prohibition, it is ferociously difficult to shake them out of it. British TV managers are indistinguishable in class, beliefs and tastes. They socialise with each other and swap information and jobs. As any anthropologist will tell you, taboo-breakers in a closed society risk the censure of the tribe.