Holy Terror: The Rise of the Order of Assassins

First, Hasan fostered an atmosphere of intense ideological commitment that produced a constant supply of volunteers willing to carry out his deadly missions

Seems like this was the first of suicidal terrorist groups.

They never engaged in the wholesale slaughter of civilians. Many of the Sunni notables who fell to the daggers of the fida'is had encouraged pogroms against Ismailis or ordered military expeditions against their enclaves

But things seems to have changed. Now most who are killed by modern terrorist groups are civilians.

Another interesting article: http://www.weirdload.com/wl-assassins.html

P.S: I bet the one who submitted this started reading such articles after playing Assassins Creed :) I did the same after I played the game :)

http://en.wikipedia.org/wiki/Mohammed_Bouyeri

For good information about the Assassins (and the Nizari Muslims in general) I recommend the books from Farhad Daftary specially "The Assassin Legends: Myths of the Isma'ilis".