Cellphone surveillance technology being used by local police across Canada

At least six police forces across Canada are now using cellphone surveillance technology, but several of them won't say whether they use the devices to eavesdrop on phone calls and text messages.

Calgary police, Ontario Provincial Police and Winnipeg police all confirmed to CBC News they own the devices — known as IMSI catchers, cell site simulators or mobile device identifiers (MDIs) — joining the RCMP, which has used the technology for its own investigations and to assist Toronto and Vancouver police.

While Ontario and Winnipeg police refused to say whether they use the technology to intercept private communications, Calgary police and the RCMP insist they only deploy their IMSI catchers to identify — and occasionally, in the RCMP's case, track — cellular devices.