As far as I know, they have been non-violent, and the crew members on the captured ships say they were treated very well. It's been about money the whole time, and they always collect their ransom. A recent one that comes to mind is the oil freighter with billions of dollars of crude, and they wanted a 3 million dollar ransom. This has been going on for a long time, and the U.S. didn't act on it until Americans were on board. Why is that? It still has impact on the economy, this global economy.
It's too easy to say let's drop bombs, let's snipe them out, let's kill everything that's not red white and blue, but that's pure ignorance.
The worst part about this hijacking in particular, is that the ship was delivering aid to Somalia, their own people, and they intercepted it for ransom.