Quote Originally Posted by skanktyme View Post
how can they tell if it is on one computer? They can't unless they are doing something illegal. When i log in from work there are 700 computers using one ip address. There are 10 ppl i work with that play. They will all show up to you guys with the same ip. There is no way you can tell they are on different computers. All you can see is the router
LOL. You can see a LOT more than just the router.
It would be trivial to create a hash of some sort based on IP, screen resolution, color depth, browser name, browser id, and then to make sure cookies must be enabled. (Yes, this is not a great hash, but it is only slightly less trivial to make a usable hash that identifies a machine more clearly)

That is much what microsoft does. It lets them say that they don't really "Identify" your computers - but it also lets them identify (to some extent) whether their software is on the same machine or not the next time it's installed.