What is the problem?

Much is now being said about the issue of Islam. Today the Australian newspaper has a story about the burkah.
That such a trivial issue has become main news and subject for public debate indicates that we as a community are no longer ignorant of Islam. Or are we?
The subject of Muslims is raised on talk back radio, on television forums, in the newspapers, by politicians and by journalists.
The debate usually comes around to the question of "the majority of Muslims are peaceful, law abiding citizens" and this statement is accepted at face value. Obviously this is a fact that is difficult if not impossible to quantify.
Also, the acts of violence that are committed by Muslims in the name of Islam are always described as acts by extremists who are always considered to be a minority.
So, my question is this, how do we identify the extremists?
Is it the clothes they wear?
Is it the way they walk?
Is it the length of their beards?

Obviously we have no real way of gauging who are and who aren't extremists. We might take comfort in the thought that those Muslims who are perpetrating acts of violence are merely a few, a minority, the exception to the rule.

I guess that in Australia we are lucky because we have a different type of Muslim to those in the rest of the world. Unlike those in Afghanistan who are constantly blowing themselves up, or in Iraq as well, or those who form ghettos in France and Sweden and Germany where those ghettos are considered "no go zones" because they aren't safe, those in Indonesia who burn down Christian churches,  in Australia we only have law abiding peaceful Muslims.
Oh, I forgot about the Cronulla riots, but that was blamed on Australian racists not those peace loving Muslims were merely provoked.

So we are a lucky country aren't we?