A new type of crime was reported last night on the news called SIM Swapping where an individual calls the mobile retailer such as Verizon and asked to do a SIM swap to another phone. If successful, they can gain access to any information on that phone including banking information. Some victims of this crime have had their bank accounts cleaned out. The only indication that you have that this occurs is your phone has no service. By the time you call to determine the problem, all your money and personal information can be gone.
What does Verizon do to protect its customers from having this happen, especially since the news story indicated that some of their employees took bribes and sold the information required to do this to the scammers. I would say if you can't trust the Verizon employees that SIM swapping should only take place in person with two or more forms of picture ID and no longer do it on the phone.