Guys ... there are two distinct strains of the Virus. MyDoom.A Targets sco.com . MyDoom.B targets microsoft.com. They are essentially the same virus so one would suspect that the same author created both programs. So Microsoft isn't so much allying with SCO as seeking their own revenge. More importantly, I would think that ANY company that was attacked in this way would retaliate.
My personal feeling is this is no better than Terrorism. While I don't support the actions of either companies, I feel that illegal, malicious attacks can not be tolerated by any of us. God only knows how much money will be wasted combatting these viruses as they clog mailboxes, and slow networks down. If you don't like the actions of a company ... protest them. There are lines between "peaceful disruption" and terrorism and this, IMHO, crosses them.