No argument on the US part. I'm still convinced that by EU laws, you're allowed to crack an app you bought in order to make it run on your software. As this hasn't been tested in court yet, though, I'll concede.
This has been tested in the Norwegian court (the famous DVD-Jon case). It was ruled that developing, distributing and applying software to make software work on your OS is perfectly legal. But then again we don't have a horde of those nasty lobbyists over here.
Cheers,
Tomas