All apps use up data in the background, thats why there are appkiller apps and task manager apps. Its minimal. Trust me, I know this stuff and I look at my data usage probably once a day. Please ring your phone company and ask them how much data you have left this month. It will be nothing compared to what you think unless you are downloading something when you dont realise that you are. Its very late here and I have to hit the pillows but please tell me what they tell you, and if they do tell you that you have used huge amounts of data they can tell you the source of it. Please can someine else weigh in on this.....