As was mentioned up thread, they will probably rush to protect the Imams and radical mosques from that "evil" backlash that they always warn us of...... you know the backlash that never happens because the majority of people are actually civilized?
.... Mentioned by one of our resident hand-wringers, right? "OOhhhh, the west is done, done,
done!!! " They're as bad as the vigil-goers. All bluster and no rational thought.
I expect the British authorities are probably a lot more brutal about this stuff than people recognize, and for sure the French are. Granting the reflexive and well-nigh suicidal protectiveness of the left, they don't represent the feelings of most.
They knew about this guy and they did nothing.
"Knowing about" is shaky grounds, though. They're keeping their eyes on probably hundreds or thousands of potential terrorists. They simply can't "do something" about all of them, and even if they're doing their best, the ugly truth is that every once in a while one will get past the guards. The problem is, in a country like the UK, governed by rule of law, subject to Constitutional constraints ... how do you keep it balanced?
Had he done anything for which he could actually be arrested? Consider carefully how you'd answer. Do you think you'd like to live in a place where being arrested "on suspicion" was the norm. After all, you post here -- to many on the left you're as suspicious and dangerous as the bomber was.