What's stopping people from taking a copy of OS X that they bought, and installing it on as many Macs as they want to? I ask because I feel I could easily upgrade my girlfriend's macbook with my copy of Lion, but I'm not sure if that's "officially" frowned upon or not. If it's okay to do it for 1 person, what about 2 people? 3 people? Where do you draw the line? Apple doesn't issue software keys for OS X, so they seem to not care too much. But still. I dunno.