Bug detectors are used to protect secure information from being discovered through the use of bugs. These can be planted in various locations and usually involve some form of recording device that can be used to pick up information that should be kept secret by security forces. Anti-surveillance technology like bug detectors is often employed by security forces and organisations like MI5 and MI6 to help keep national and international data safe.

Bug detectors are used to pick up suspicious signals so that the devices producing them can then be investigated and destroyed if required. Bug detectors may be used in a discrete way, being carried in pockets or items of clothing, or they may be combined into other systems. They can pick up a range of signals, even from devices that only give off a weak or sporadic signal. This makes them highly effective and renders them essential in matters of security.