Canadian police used BlackBerry’s key to unlock BBM messages
http://www.engadget.com/2016/04/14/rcmp-blackberry-bbm-encryption-key/
http://www.engadget.com/2016/04/14/rcmp-blackberry-bbm-encryption-key/
http://arstechnica.com/information-technology/2015/12/microsoft-may-have-your-encryption-key-heres-how-to-take-it-back/