Last term the son of a senior businessman got caught helping himself to another child's iPod and was suspended from his fancy London school.

This story of petty larceny is of keen interest to about a dozen people. To the businessman - who doubtless gave the boy a rocket - to the boy, his mother, his headteacher, his victim and the classmates who will have enjoyed the shiver of excitement that comes when someone else gets into trouble. Otherwise no one cared.

I happened to hear about it last week and didn't care much either. Yet the story made me wonder what might have happened - let us just suppose - if it had not been a businessman's child but Barack Obama's sweet-looking elder daughter who had taken it into her head to pinch a classmate's iPod. Then rather a lot of people would have cared: in fact it might have cost her father the US election.