Full scanns can for sure stop passengers from introducing non metallic weapons abord. Those already exist and cannot be detected without such a light ray scanner. But cannot be detected a swallowed plastic bag full of liquid explosive with a combined chemical substance as time clock detonator inside the stomac. Such a human body bomb needs to be discovered ahead of boarding by other scanners which usually are only used on arriving passengers suspected of drug trafficking. This threat needs to be adressed urgently, too. Money needs to be invested in more performant scanners which allow fast traffic, too.

I don't like the idea of all this security. Not that I am up to anything. I just don't like the idea of minders being around every corner, under every bush, listening to my correspondence and treating common people like the enemy. I am not, now if some one really wanted to do harm they would. The reason why terrorism happens has more to do with the dynamics involved than anything else. You can have thought scanners and still miss things. You can either improve the fundamentals of the global mechanic or you can increase security. If you encouraged proper fundamental economic activity across the planet you wouldn't need the police state. Most of the armies could be put on reserve status and remodeled into developmental organizations for the youth and large infrastructure projects.