Tracey Follows tests what happens when you power down your phone. Some devices send roughly 50 MB of data nightly around 2-3 AM even when off, transmitting usage updates and other information. One tested phone didn't do this, raising questions about which devices are actually sleeping.
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So when you turn your phone off, if you've got an Android or an iPhone, people think the phone's turned off, but it's not, is it? That's correct. What's it doing and what can it access?
We did a test with our device and the other guys' devices, and every night the other two guys' devices send about a 50-megabyte burst of data around 2 to 3 AM. And what is that? That's the phone calling home with your comings and goings and a data update about what that device has done that day. And it's shocking. Ours doesn't do that. But, and so even if you turn it in airplane mode, the phone will do it itself once it connects to a network, any kind of network again. Yeah.