ECM sounds like something from an FBI telly show, but not something that would be used in real life. At most, we can imagine it be used by the police or military as an anti-terrorism measure. As far as, for example, bug detection goes, we associate it either with spy movies or perhaps corporate espionage or the mafia-in other words still spy movies.
This isn’t true of course-various forms of sweeping and electronic counter measures are more common than we know. Large corporations like Google will, for example, restrict data transmission via private cell phones in parts of their buildings, or electronically soundproof a meeting room. Similarly, this kind of measure can be a part of airport security.
While we are all used to pat-downs, security scanners or metal detectors, all part of the necessary procedure to be allowed onto a plane-in case of an actual emergency or bomb threat, many airports have far-reaching technological aides.
Electric Counter Measures can take many forms, though the simplest two are the disconnection of any sources of Wi-Fi or hotspot, and, in a second stage, all mobile networks altogether. This means, for example, that a cell phone activated bomb, as clichéd as that sounds, can no longer be activated via call-the signal simply wouldn’t go through.
In normal situations, this kind of measure would be completely illegal-if someone was to, say, carry an ECM device into a public building and activate it, they would be breaking the law in most countries on this planet, police, army and specially licensed security agents are allowed to use such measures as is necessary.
There are drawbacks too, however-most devices will block all signals, incoming and outgoing, so communication for security forces can be hindered too-though there are some forms, such as walkie-talkies or certain unblocked frequencies that can still be used. Calling an ambulance or the police would be impossible though.
However, turning communication devices into useless hunks of metal isn’t all ECM is good for-they can also be used to spot bugs. Normal recording devices will either emit a constant transmission-these can be blocked and spotted via that signal, or they simply record and have to be activated manually. Spotting the second kind is harder-the data that is collected is much more at risk though, since it isn’t saved anywhere but the bug itself-James Bond and the recording pen come to mind.
All in all, a comprehensive set of Bug Detection and Signal Jamming makes for a very secure airport in emergencies.