Law enforcement and intelligence agencies require the ability to intercept communications when appropriately authorized. Canadians deserve to know the circumstances under which their communications may be intercepted. The widespread use of International Mobile Subscriber Identity (IMSI) catchers in the United States, also known as Stingrays, combined with the fact that Canadian agencies refuse to even acknowledge owning the devices, continues to fuel debate.
The use of IMSI catchers poses serious privacy risks. Unlike traditional wiretaps, which selectively intercept calls to and from a specified target, IMSI catchers pretend to be a cell tower and capture information from every cell phone in the vicinity. It is impossible to target specific mobile phone users with these devices; they scoop up information from every phone within range.
You can read the full article here.