There is absolutely nothing wrong with being religious, keeping a beard, or criticizing Western foreign policy. It is also acceptable, even admirable, to be politically active and lobby to influence said policies. However, advocating any illegal activity is crossing the line. Anyone who doesn't understand the difference is just stupid.
Having said that, I don't like this policy of 'no comment'. People should have the right to face and refute any accusations against them. This business of secret evidence is very troubling.
As for immigrants becoming radicalized, I fully support the recommendations in Europe (and, I think, Australia) to mandate that all religious leaders should be locally trained and, ideally, locally raised. By law, you can't mandate 'locally born', but locally raised should be a minimum requirement so these people are in tune with the local culture.