fi said:
how does he stop and search a suspected bomber? Did I get what you said?
I think so. In this instance, his actions was followed from his house. Suspicion was raised because he lived in the same block as terrorist suspects and he wasn't white. Two possible things occurred.
1: they simply followed him but didn't do anything - why? why wait until he was in a place where, had he been a bomber, he could kill so many more innocent people (like letting him onto the bus);
2: the officers watching the apartment called for others to track him down, in which case - what if he HAD been a bomber?!? That bus could have been the target. What, then, would the point of surveillance have been? ("Yes, he's leaving the apartment... he's got on the bus... the bus has been destroyed... yes, we're pretty sure that was our man, sir.")
Why was he not stopped upon leaving the apartment block, or at least as soon as he was far enough away that the actual terror suspects would not have been alerted to police presence? Why was he able to board a bus, alight, go into a tube station, swipe his travelcard and head down the escalators?
fi said:
And that being the case, how can you prevent a bombing situation?
That's the question. To my mind, the only possible way is by intelligence - see the Birmingham arrest for an example. If intelligence is foiled, bombs will go off, people will die. You could heighten the security in tube stations, etc - post armed police at each station. This would probably deter terrorism, but only if it succeeds in creating an atmosphere of fear and caution, much like American airports where you really do believe that if you twitch you might be shot. Personally, if I wanted that I'd live in America.