Crash,

It only has to happen once for a tragedy to occur. No-one checked the soles
of your shoes for explosives until someone tried to blow up something with
explosives in their shoes either. A perfect example of not bothering with it
until a tragedy occurs.

Nope. A perfect example for understanding that there will always be a risk.
There is no total security. The question is: How much freedom do you give up
hunting the elusive "minimal risk".

When someone takes some pics of a plane, and those
pics are found in the apartment of someone who's just blown themselves and
your best mate up with that same plane somewhere down your street, will you
be complaining why nobody did anything when they saw him taking the pictures
at your local aerodrome?

No. Why would I? There is always risk in life.

--
Thomas Borchert (EDDH)