Took a philosophy class this semester. (BORE)
But we did a two week study on terrorism and war, and whether or not they were morally acceptable practices. During the study we discussed Just War Theory, and the underlying principles of Jus as Bellum (The Right to go to War) and Jus ad Bello (Practices during war). I tend to not see many flaws in Just War Theory, but for those of you who are pacifist, you can check out Anti-War Pacifism and all that jazz.
Link for those interested: http://en.wikipedia.org/wiki/Just_War
Basically if you can justify your actions, whether they are predatory, vengeful, moralistic, religious, or political, while adhering to the Just War Theory, then terrorism is fine. Most people believe that there is NEVER a moral form of terrorism as the negative right to life overrides your positive right to fight for your rights, beliefs, or whatever. (Look up Haig Khatchadourian for more on this (sp?))
I believe that occasionally terrorism is called for and needed in revolutionary situations, but in the case of this story, terrorism is not called for and therefore they should be punished. There were multiple other mediums they could have conveyed their message, and resorting to violence was not a last resort. That being said, this does not adhere to Just War Theory and should not be carried out.
Definition of terrorism: the use of violence, or threat of violence against unarmed innocents in order to gain political, religious, or predatory, goals through instilling fear.