Forget the whole "they came at us with knives, so we gunned them down" defense that Israel is putting forward for their attacks on the Gaza relief flotilla.
They attacked the flotilla in international waters. You do NOT do that. It is just about as illegal as anything can be in international waters. It is pretty much an act of war. It's also blatantly stupid besides, since it means that your civilian ships are now fair game.
That all this was pulled to stop humanitarian aid from reaching Gaza is just insane.
Edit: There appears to be a video of the beginning of the attack, and it appears to show the commandos firing first. And what the hell is going on with twitter? They seem to be blocking hashtags about the incident. They were all over Iran.