I done it the other week,shat myslef and felt like a right twat lol Ive always belived it's because of the radio signals off your phone which cause the pumps to knacker up.But my freind told me theres sensor underground which tell the person at the counter which pumps are leaking and useing your phone could f**k them up. what is the actual cause and why? has anyone actually done it before,it'll make me feel better if you have lol