My daughter lost her iPhone 5s with iOS 8 on it. However the battery had gone flat so we couldn't locate it! I put it in lost mode and blocked the sim and IMEI so everything was disabled on it. The phone had been lost for 5 days when someone tried turning it on, it notified us using a wifi address that it had never used before! So how does it log on to a wifi and transmit its location if it doesn't know the password to the wifi? We did get the phone back finally and all is good now. But how does that work, it has baffled me because in couldn't use the cellular because the sim was blocked?