Silver Miller a cryptocurrency-focused law firm based in the U.S., says it has filed arbitration claims against AT&T and T-Mobile on behalf of victims of "SIM swapping" cellphone hacks. By leaving holes in their security protocols and failing to properly train and monitor their employees, cellphone providers have assisted thieves in remotely taking over the SIM cards in people's smartphones, accessing financial records and account information of the victims, and emptying the victim's accounts of cryptocurrency and other valuable assets."