An anonymous reader quotes a report from CBC.ca: The RCMP for the first time is publicly confirming it uses cellphone surveillance devices in investigations across Canada -- but at the same time says the potential of unauthorized snooping in Ottawa, as reported by CBC News, poses a threat to national security. The RCMP held the briefing in the wake of a CBC News investigation that found evidence that devices known as IMSI catchers may be in use near government buildings in Ottawa for the purpose of illegal spying. After shrouding their own use of the technology in secrecy for years, the RCMP took the unprecedented step of speaking publicly about the devices -- also known as Stingrays or Mobile Device Identifiers (MDIs) -- to address public concern amidst mounting questions about their use. The RCMP says that MDIs -- of which it owns 10 -- have become "vital tools" deployed scores of times to identify and track mobile devices in 19 criminal investigations last year and another 24 in 2015. [RCMP Chief Supt. Jeff Adam] says in all cases but one in 2016, police got warrants. The one exception was an exigent circumstance -- in other words, an emergency scenario "such as a kidnapping," said Adam, whose office tracks every instance where an MDI has been used by the RCMP. He says using an MDI requires senior police approval as well as getting a judge's order. And he says the technology provides only a first step in an investigation allowing officers to identify a device. He says only then can police apply for additional warrants to obtain a user's "basic subscriber information" such as name and address connected to the phone. Then, he says, only if the phone and suspect are targets of the investigation can police seek additional warrants to track the device or conduct a wiretap to capture communications. Adam says the RCMP currently has 24 technicians trained and authorized to deploy the devices across Canada. He knows other police forces own and use them too, but declined to name them.