Security Screening

suitcase  screening  device (web picture)

People and their luggage get scanned  at airports, major bus terminals / train stations, malls, courthouses, and other public facilities  (at least this is the case in Israel) - the purpose of that being to detect concealed metallic or non-metallic security threats (knives,weapons,explosives, certain liquids/ gels/ powders/ plastics).

body screening (web picture)

handheld scanner (web picture)

There's little accurate information as to the potential health effects of these screening systems. It is generally argued that there isn't much risk, if at all, but I personally believe there is. It's not a one-time thing, and radiation accumulates. The more you go through airports and all the other places where you get screened, the more radiation you absorb.

They say the detection  is only about 50 percent successful, so maybe it's not worth the trouble. Unfortunately, it has to be done. We live in a nightmarish world in which terrorism reigns and governments are helpless against it. Prevention through detection is our main real hope.

As for success, well, we invest  millions in things that we know in advance that there will be very little success about them, and yet we do it, we have to do it. For example, all those reabilitation centers for drug and alcohol addicts, or for released jail prisoners. Most of these people return to their old habits and pose a risk both to themselves and to society. Nobody will dare suggest to give in and close the above mentioned centers.