There's a line on my AT&T family plan that's on a 2gb data allotment a month. It's my sister's iPhone 6. The entire month was well under the data quota. Last night, I get a message saying about ~1.3gb has been used this month. I say to myself, "Okay, the billing cycle restarts on the 6th, it'll be okay ..." I had the same problem on her very recently iPhone 4S. It would gobble chucks the last week of the month in 50mb pieces. Thought that it was an issue with the old phone. When I set up her new iPhone, I'd gone and double checked to make sure she had turned off auto-updating on EVERYTHING. She'd only had about a dozen apps installed and doesn't play too many games on it. There's nothing to make me think any usage has changed in the last 28 days. WRONG. Checked the recent activity on my account ... 300mb and another 500 mb at two points in the day today. I'm like ... WHAT?! Any idea what's doing this? I'm fuming. Not sure who to be mad at. Honestly tempted to cut her line.