I just reread this thread and noticed your post about restricting our right to make backups. That is a good point. But this is the problem with electronic technology, that backup can be distributed and who the hell is going to find out. If you make it copyable, then it is copyable for everyone, causing piracy. I can only think of one method that might work, although it's not entirely enticing or plausable yet:
Online serial number authentication. You cannot start the game until you log on and your serial number is authenticated, similar to Neverwinter Nights. Should yor serial number be used more than once simultaniously, alarm bells ring. This idea is based on the design of DNS security. This is looking at a time where all machines are permanently connected to the 'Net.
And even then, how long before people produce fake authentication proxies...
It isn't our problem to fix this situation; it's the software houses problem. Millions are spent on the latest protections, and they all get cracked! I like the idea of CD keys (online maybe) providing there's scope for multiplaying without participation on the software houses servers (Direct IP).
I'm not saying they shouldn't protect their software, i'm just saying they shouldn't protect the disc! Look at Microsoft software; all copyable, but look how much money they've made. Piracy hasn't made them bankrupt. This proves there are alternatives to the disc.