So, my brother's iPhone 4 SIM card gets deactivated because he got a different phone. And then today, I noticed it had a missed Facetime call. I didn't return it, but, I tried entering my friend's phone number in the contacts and then started a Facetime with her, and it worked! Needless to say, I was surprised. I'll ask my friend what number it came from, on the off chance that it was my brother's phone number. I'll post back/edit in a few. EDIT: Okay. So, the call did come from my brother's phone number. But the SIM card had no service, and wasn't active.