The best thing that these guys could do, would be to make a logical push to help Linux get deployed at large business. Hitting back at the "mean" superpower will accomplish nothing but make them look like jerks. Get the masses to work against MS and then the can get something done. Most of the vulnerabilities that have been found recenlty require so many, what-if's to be in place before they work that it is unlikely that anything will be put in the wild to take advantage of this. Would be much easier to create a Flash based attack on the general public and be done with it. I am sure that MS weights the potential use of the threat when they develop a plan of which items to fix. The assumption is always, that the newest item that we know about is the most dangerous, but that is just a narrow perception of what is going on.