… As for who might be behind it, Goldsmith says IMSI catchers are used by law enforcement, federal agencies as well as organized crime and foreign intelligence. Based on the configurations suggested by CBC’s results, he believes the IMSI catchers detected in Ottawa could be foreign made. “We’re seeing more IMSI catchers with different configurations and we can build a signature. So we’re seeing IMSI catchers that are more likely Chinese, Russian, Israeli and so forth,” he said.