Stingrays are surveillance tools used by the FBI and police across the US. Sen. Ron Wyden wants to know if they're messing with your phone calls.   

The Democrat from Oregon submitted a letter on Tuesday to Federal Communications Commission Chairman Ajit Pai, requesting information on how the phone tracking devices could interfere with calls to 911, with internet access and with gadgets like hearing aids.   

Stingray setups pretend to be cellphone towers while they're actually snooping on nearby devices, intercepting calls and text messages. Because Stingrays, otherwise known as IMSI catchers, are subject to FCC regulation, Wyden wants to know how they've been tested for public use.