I will give way in a second, but I want to make my argument in my own way.
Jean-Louis Bruguière, France's top counter-terrorism investigator—it was reported in The Times on 1 June—claimed that identity cards would help Britain to protect itself from terrorist attacks. The head of Interpol said that in cases of terrorism multiple identities have been used by terrorists. The quantification of the benefits depends on the assumptions that we make and the programme that is established, but they are of the order of at least £0.5 billion a year. It depends on how fast the various benefits come on stream—the Criminal Records Bureau benefits and so on—but in sum, the benefits of this ID card system, first to every individual who has one, and secondly to the society, are real and substantial.