Once I had my SIM card stuck in my phone. So when I wanted to use a different phone, I bought a new SIM card kit online and brought it to a T-mobile store. I told the clerk my SIM card is stuck in this phone so I want to transfer my number to the new SIM card. He asked for my phone number then scanned the new SIM card and transferred the number. I didn't have to provide any identity or proof that I actually own the number. It's scary how easy stealing someone's phone number can be.