You do realize it's nigh impossible to stop a DDoS attack right? All that's involved is sending lots of information to the servers at the same time. It's the LIVE log-in server that goes down which is easily accessible via well... anything. You realize how many services use a LIVE log-in? Outlook, Bungie.net, Office, Windows 8, Windows Mobile, et al. You shut down the log-in and the actual servers might as well be down. Here's an easy example, if a small fraction of people on facebook all hit F5 at the same time it would pretty much constitute as a DDoS attack because of the amount of data being sent and received.