I also posted this in iOS 10, but just realized this may be the better sub forum for it. Has anyone seen this before?! Went to bed about 1AM last night (not on WiFi) and woke up this morning to a HOT iPhone and messages from Verizon saying I've used all account data (18GB) as well as $250 in overages. I did not start any download or anything like that and wasn't doing anything with it before bed. Verizon said the heavy usage was from 1:30AM until the time I called them (about 9 or so). I have used every flagship iPhone since the 4S (except the 5s) and have never had a problem like this. The data tracker in the screenshot was reset just over a month ago, and no other service or app even comes close to that usage. The closest is Facebook at about 1.5 GB. I can understand a third party app going off the rails on data (to an extent) - but an iOS system service? On cellular data no less?! You would think iOS is smarter than that. The only thing I can even think of is that I synced my recently added playlist to my Apple Watch yesterday but that is only 100 songs. Even at 10MB each, that is less than 1GB. I checked my music stored on phone and that comes in at less than 700MB. Called Apple and they submitted it to engineering and told me to expect a response in a few days. Called Verizon and they basically told me to go fly a kite, it's not their problem. Any ideas?! Totally irritated. The Verizon rep told me not to go to sleep without my phone on WiFi - umm okay, I don't try to but it can't always be helped - not to mention I've done it many times before and never had an issue. Sorry for the lengthy post but just hoping to get some ideas or see if anyone else out there has run into this.