Irish Pride and the IRA

There is a group you may have heard of called the IRA (Irish Republican Army). This group wants Ireland to be a country independant of Britain. 5/6 of Ireland already is independant, but the IRA wants to gain the other 1/6. They do this out of pride of Ireland. They believe that Ireland is only part of Britain because of the bad misfortune of its location, and in many ways, they are right. Irish pride is associated with the IRA a lot.

The issue becomes controversial because the IRA, until recently, fought against "British Tyrany" with bombings, arson, and many other types of guerrila warfare. Many innocent British were killed in the crossfire of this political war.

The question I pose unto you, is whether these attacks justified, or was this behavior not justified and why? Both sides' arguements are welcome, but I must ask you explain in as much detail as possible.