According to the news, the ships were asked by the IDF to dock in Ashdod instead, where the goods will be inspected then loaded on trucks to be sent to the Gaza Strip. The flotilla refused to do it so the IDF boarded the ships to forcefully bring them to Ashdod. All but one ship agreed peacefully. That ship, I think it's the Turkish one, had lethal weapons like knives and pistols on board. An IDF soldier was even thrown by "peace activists" overboard. The IDF opened fire to defend themselves from lynching. I am not saying what Israel did was right, although we cannot really say that the passengers of the Turkish ship were "peace" activists because first, they carried weapons with them and second, they attempted to lynch the soldiers. Right now, the goods are being inspected in Ashdod which will be transferred to Gaza. They attempted to breach the blockade so the IDF has full rights to stop them. AND--Israel was not the only country who imposed a blockade on Gaza. Egypt did too. Do you think Hamas can be trusted? I don't think so. Last year (2009), Hamas confiscated thousands of humanitarian aid donated by the Jordanian Government to the Palestinians in Gaza. And lastly, how come those "peace" activists did not plan to negotiate Schalit's (Israeli soldier that was kidnapped by Hamas) release? That flotilla is surely one-sided.
EDIT: Watch this: