I'm not a member of any movement, Anonymous or otherwise. The point I was trying to raise: civil disobedience is disruptive by nature and will inconvenience and annoy - but it is far from immoral. Why should a DDoS be considered any differently? The methods of physical and virtual protest are different but their ends are the same.
But methods matter, unless you want to argue that the ends justify the means. Which would be a bit of a stretch in this case, by the way, since the most likely ends range somewhere between nothing and causing a bunch of problems for people who have had nothing to do with this whole story.