Stolen iPhone and can't see on find my iPhone Someone stole my iPhone yesterday and Find my iPhone was on. We were tracking the place and then they might have turned the phone off because it appeared offline. Today I couldn't find my device on Find my iPhone. I was using two phones with the same Apple ID, and I can only see one phone now.  

What does this mean? Did they just erase my phone and set up as a new phone? I blocked IMEI number and it was passcode protected as well.
If the phone disappeared from Find my iPhone on iCloud (which is different from being offline), someone must have removed it.
Even if the thief turned it off and reset it, it would remain on iCloud as an offline device until the account owner removes it.

On a side note, if the IMEI lock disables data on the SIM, it makes it difficult if not impossible to find the phone unless the thief goes to a place where the phone has connected to a wifi network before.