Comment by aviv

Worse. Some very large carriers don't even look at the supporting documentation (bill, LOA) submitted with port orders unless there's a rejection from the losing carrier and they want to double check the address entered or something. Hijacking numbers is crazy simple. Same for hijacking the SMS functionality of any number in the US (voice traffic remains untouched). In about 10 minutes you can start receiving SMS directed towards any number you want, and also be able to send out texts originating from that number. Anyone who relies on SMS for any type of authentication should stop.