Some illuminating statistics via Juan Cole:
"A Europol report on terrorist attacks in Europe in 2009 [pdf] says that out of hundreds of terrorist attacks iin Europe in 2009, most were the work of ethnic separatists. About 40 were carried out by members of the extreme left. A handful by the European far right. See also this analysis.
One terrorist attack was carried out in 2009 in all Europe by persons of Muslim heritage (I do not say ‘by a Muslim’ because terrorism is forbidden in Islamic law).
That is right. Out of hundreds. Exactly one."
Incidentally, not to nitpick on this one, but I find it rather risky to say that terrorism is forbidden by Islamic law. Someone will always be able to find a legal justification for terrorism, which also depends on how terrorism is defined. No religion can confidently exclude such legalistic perversions of original intent.