An IMSI Catchers, also known as Stingrays or rogue cells, are readily available as commercial products as well as do-it-yourself projects running open-source software, and are obtained and used by law enforcement agencies and criminals alike. In this presentation we discuss multiple detection capabilities from the network operator’s point of view. We draw a comprehensive picture on current threats against mobile phone devices and networks, including 2G, 3G and 4G IMSI Catchers and present detection and mitigation strategies under the unique large-scale circumstances of a real European carrier. One of the major challenges from the operator’s point of view is the fact that cellular networks were specifically designed to reduce global signaling traffic, and manage as many transactions regionally as possible. Unlike popular belief, a network operator does not have a global view of its network by default.