Mac users like to talk about how Mac OS X doesn't have any activation. How it's all about how Apple trusts their users and such.
Personally, although I agree that activation can be user unfriendly, I totally sympathize with Microsoft for implementing it. Let's look at the differences between Windows and OS X here:
| Windows | Mac |
| You can buy Windows from anyone. Specifically, you can buy a PC running Windows from almost anyone. | You can only buy Mac OSX and Mac's from Apple. Apple doesn't have to worry about rogue OEM's installing bogus copies of Windows |
| Windows is hugely pirated | OS X is probably pirated somewhat, but Apple can be sure that for each Mac, they've sold at least one OS X license (the one that came installed) |
| You can install Windows on any PC, and MS is a software company | You can only install OS X on macs, and Apple is a hardware(/software) company |
Given all these differences, it makes sense that MS invests so much in this technology. When your software is running on bajillions of machines, you know there are people trying to screw you somewhere.