I have been threatened occasionally. But that happens to everybody who is writing this kind of things. Threats will come without fail. It might happen to the most 'innocent' texts. If it gets too much we call the police.
I agree that it is not just the extremists who harbor bad thoughts or engage in bad acts, but they are usually the source of the polarization and try to keep education and communication of the main stream from moving forward.
What is important is that one utilizes one's intellect and not to be 100 percent sure about one's convictions. One should always leave room for doubt.

