body scanners not very good at finding explosives

i have posted this once before but it did not get any hits i thaught it is quite inportant so i am posting it again heres the link news.bbc.co.uk...

it just seems a bit strange that if they cant pickup explosives what is the point of having them is it just a nother way of degrading the puplic and for macking every one toe the line to get us ready fo the police state