Finally.

I've been waiting years for an article by a Muslim person citing that the Muslim community itself needs to do something about Muslim extremism and radicalization.

This is a problem that non-Muslims can do nothing about.  We do not understand Islam, we do not go to Mosques, we don't understand nor are able to detect the difference between the early stages of radicalization and someone who is simply especially devout.

Next step:  Muslims the world over should be speaking out, denouncing these extremist acts.  When a Danish cartoon results in riots the world over and deaths, but people murdered in the west creates barely a whisper, all it does is lend credence to extremism.

The best defense against radical Muslim extremism is for Muslims themselves to denounce it as non-Muslim, barbarism, and unworthy of any respect.  Until that happens, the silence on these matters gives non-Muslims the perception that the silent majority of Muslims secretly agree with these actions.