Anonymous is rational, in much the same way that the evolution of stupid, mindless beasts is rational because it follows a path of self-interest. Maybe this is just a joke. But my theory is that Anonymous is stepping onto thinner ice then it's used to with it's support of Wikileaks. I doubt they will be destroyed, but people could very well get in trouble. In anticipation of this, Anonymous is making it so any legal charges brought against it or it's members will be charges brought against "That group that declared war on snow". Prosecutor says, "These people are dangerous subversives, threatening the well-being of democracy" Defense says, "You mean the 13 year old whose latest evil act is attacking snow?". The general public, with no real knowledge of 4chans anarchic approach, who can't really take the internet seriously, see a teenager bitching about snow, and lawyers saying that they are a national security risk. Hello dismissal of charges, and lots of embarrassment. Ity may not be a foolproof plan, but its a plan whose biggest risk is, "We do something kind of funny"/
Or, you know, they don't like snow and want to dick around. That's also possible.