Id hardly blame the revenue, (although I concede they are ultimately responsible) its entirely the fault of sucessive governments not having the balls to actually change the law to make this stuff illegal. Despite the ridiculous nature of the percentage they pay, what Apple et al are doing is entirely legal.

You can hardly say to a greedy foreign corporate that they have to pay a bit more UK tax than the law allows, so that everyone in another country can be better off. They only care about their share value/profitablity.

If David Cameron etc want to get more revenue, change the appropriate tax laws to get it!