Electronic bugs is also known as a covert listening device, more commonly known as a bug or a wire. A bug does not have to be a equipment usually designed for the purpose of intercepting. For example, with the right technology/software, it is possible to remotely activate the microphone of cell phones, even when a call is not being made, to listen to conversations in the vicinity of the phone.
The use of electronic bug is often a race to gather critical data before the devices are discovered and removed[like spying or for security]. For instance, place where confidential-secret activity occurs are frequently examined, or “swept”, for bugs.