But experts say a new scanner which can read minds is the next step in fighting terrorism.
Inventors also claim it will slash queuing times at airports - and bring an end to a ban on liquids.
The device, dubbed MALINTENT by inventors, uses sophisticated sensors to read body temperature, heart rate and respiration.
Analysed together, these factors can lead security services to potential terrorists.
Any suspects are pulled aside for questioning and then subjected to a second scan, which involve micro-facial scanning.
This equipment is able to read minute muscle movements which give further indications of criminal intent.
So far it can recognise seven primary emotions and emotional clues and will eventually have equipment which can analyse body movement, an eye scanner and a pheromone-reader. More...