Thank god publishers and developers haven't had the bright idea to extend this to physical computers as well. It would suck to have games you can only install on authorized hardware (e.g. Alienware, HP).
Securom says hello
https://en.wikipedia.org/wiki/SecuROM
edit: not specific hardware, but they tried to limit to the few instances of hardware you own. changing your cpu/mobo would qualify as an instance. You initially were given *three* installs. This is the mindset that some publishers have with their product.