The tyranny of data protection

Am I the only one to be constantly asked by corporate call centres to prove who I am?

It would be quite understandable, of course, if I had called them – but they are calling me. I got the third of these calls in the last few weeks last night, and it was from British Gas. But I am not, however many times they bleat 'data protection' at me, going to tell them my date of birth or any other personal details over the phone. They will be a good deal more certain about who I am than I can be about w...