The problem with pacifism is that there are always people out there who will use pacifists for target-practice. In those situations, pacifists become a dying breed. Think about China. Years ago, hundreds of students protesting in a non-violent way. And the army just driving around with tanks and guns and basically kick the hell out of those pacifists. No wonder that even in extreme situations, pacifists start to think about self-preservation and start becoming violent...

Being a true pacifist is extremely difficult and will probably get you killed. Or at least cause you a lot of troubles in life. Ever heard about Ghandi? Seen the movie? That guy was a real, extreme pacifist. He got beaten up, sent to prison for several years and was basically spit upon by quite a few people. Only to end up being shot by one of those people for whom he did all this. You would think that the people who followed him would use the same principles but no... There's always some pacifist who defends pacifism with all possible weapons.

Technically, you could call G.W. Bush a pacifist too. He has the control over a huge army and best of all, nuclear weapons. He can force others to stay peaceful, or else...

It's all about control here. Those protesting people want to speed some process of bringing peace to those areas up a bit. Violence has a tendency to speed things up a bit, but it also tends to go wrong in many cases. Say, for example, there's a cow on the road and you want her to get off the road. Talking is no use because she won't listen. Bribery through offering some grass might lure her off the road, slowly. But she could decide to walk to you, eat some grass and then walk back on the road. No, the fastest way is to kick her in the ass and then watch her run away from the road...
Or watch her turn around quickly before she impales you on her horns. Violence can lead to more violence...