It is hard to know exactly what he is worth, for the Bono stash is managed with unusual sophistication. Estimates range up to £250 million, but he shows few signs of wanting to let much of it go, and why, you might reasonably ask, after 20 years at the rockface, should he? His band is, undeniably, one of the best, most enduring and creative in popular music's history. Yet Bono's enthusiasm for amassing and creatively sheltering his personal fortune carries with it a smack of hypocrisy that many, even those prepared to listen to his message, find troubling.