They were actually charged and went to prison.
Kinda weird actually considering they were operating on their own government's orders.
https://en.wikipedia.org/wiki/Sinking_of_the_Rainbow_Warrior
Can you imagine, the government telling you to do something and then dragging you in front of a court after you do it :S I don't think they should have gone through with it but as they were under orders I don't think the responsibility lies with them.
By the way I really miss the way Greenpeace is no longer a grassroots environmental organisation. Protesting against nuclear testing, whaling etc the way they did was risky but effective.
Nowadays they're just another multinational corporation, just with some environmental goals. It's no wonder they're never really in the news anymore. And the need for this activism is actually much greater than ever now.