There’s an interesting thread going on at the Apple Support Forums from a number of users who are finding that their iPhones seem to be transmitting data in the wee hours of the morning. Somewhere between 1 AM and 4 AM users are reporting late night data usage from a couple of kilobytes to 75MB  and no-one really knows why. It’s far too large to be from visual voicemail, push notifications, or crash reports, and it seems to be hitting people consistently.

Late night data usage AT&T iPhone

Without official word from AT&T or Apple, it’s not known what’s causing this data drain. One possible explanation is that AT&T is consolidating a big chunk of the day’s traffic, and only processing it in the early morning. What’s incredibly odd, is that a number of affected customers are using WiFi, so theoretically the iPhone should not be using any data.

This creates a major problem for consumers who are on fixed data plans. The increased usage nightly can easily impact their plan, causing costly overages. AT&T encourages customers to manage use of their data, but that becomes difficult when the carrier might be responsible for phantom data usage.

Any of our users experiencing big data spikes at odd times?

Source iLounge