Because they are BAA security they think that they are the untouchables - if you even were to dare to think about saying anything then you can just imagine what they would do - the Police there in no time.
I find them pretty useless - they have no idea of customer service - and for BA most passengers assume BAA and BA are one and the same.
They really should go to some overseas airports and see that security can be done with professionalism and courtesy.....
FD