One of the little-talked-about dynamics of the mobile phone industry is the huge proportion of profits that come from the 2-3 per cent of people with very very large Pay As You Go phone bills. These people spend £100-£200 per month on their prepay phone bill in the UK; double or triple the cost of a contract phone (and ten times the average for prepay). What makes you pay thousands of pounds over the odds on your phone each year? Could it be that prepay phones can’t be traced? We’ve all seen The Wire.

As a result, mobile phone numbers appear on everything from colourful cards in phone boxes advertising personal services, to rocks in remote valleys of Afghanistan recruiting jihadists for the Taliban. The very small number of very high spend pre-pay mobile phone customers provide 15-20 per cent of the profits of consumer mobile phone businesses in the UK. That’s billions of pounds of profit from enabling anonymity.