If Greece did not want the boats to leave from Greek ports it should have simply told the organizers beforehand to start their voyage elsewhere. Cyprus did this. In proceeding as they did the Greeks actively (this is the point) sabotaged an undertaking which was none of their business. It is clear that the Greeks were put under extreme pressure to act this way. This is has not been lost on anyone observing the flotilla saga unfold.
Islamic State militants blow up ancient Arch of Triumph in Palmyra (Reuters)
from the article: In dealing with flotilla, Israel is anything but smart