Also, using a device known as a StingRay, law enforcement agents can send tracking signals inside people's houses to identify the cell phones located there.
另外还有一种设备叫做“魟鱼”，（即“IMSI捕手”） 执法机关能够在人们家里发送跟踪信号， 来确定家里都有哪些手机在工作。