When you enter the multiplayer lobby the game registers the CD Key that went online and Bungie gets a list of how many specific people played the game (each CD key is independent and will not work on more than one computer at a time.) This is how they get a count for how many people are logging in to play every day/week/month, and they'll know your CD key because it'll be on that logged list that he pulled on the 26th. If you ever even went into the multiplayer lobby you're good as long as you still have your (independent) CD Key. If you lost your Key and still have the game on your computer you're in luck. [url=http://www.halomaps.org]Halomaps.org[/url] has [url=http://hce.halomaps.org/index.cfm?fid=4547]a Cd Key recovery tool[/url] that will tell you what your specific CD Key is. [Edited on 08.07.2010 9:14 PM PDT]