Sorry Ludwig I just realised I didn't actually respond to the point you were making.
"people who spout hateful nonsense shouldn't be dismissed lightly. "
I can see the argument here... and I'm sure they're not dismissed lightly by the security services (well, I hope they're not anyway) and they deserve to be persecuted if they do something dangerous, or if the authorities have convincing evidence that they will attempt it.
But for the average person on the street, I think dismissing them is actually perfectly fine. Some of us have been the target of one rabid hate-preacher or another for as long as we can remember - the only difference with people like Choudary is that the target of his hate is the entire civilized world rather than just a section of it.
To tell the truth, deep down I don't *really* believe in censoring or prosecuting hate speech. I think it causes more problems than it solves. If that means letting idiots say what they want, then I'm okay with that.