AP article titled “US suspects listening devices in Washington” Outlines new concerns in Washington on the use of cellphone-site simulators by foreign powers or criminal networks. These very controversial devices have been illegally deployed by law enforcement for years. They have the ability to mimic a cell tower and sweep up all communications in the area of surveillance.
For a better understanding of this evasive technology you might want to watch this video.
Know that this is not only an American issue the CBC reported the RCMP admission of it’s use.