StingingVelvet: I don't feel like digging up links right now, but there are several cases where judges have ruled that without cracking for the purposes of redistribution or resale there was no infraction.
Tom's Hardware has a page describing the DMCA revision. The language used in the revision is that one can crack software for "investigative" purposes, so long as no copyright breach is intended (as fair use). In this sense, it's no more harmful than modding, in the sense that the recipient/developer of the crack must own a copy of the game to use it. Cracking does not promote the illegal distribution of games any more than the manufacturer not including DRM does.
The norm is quickly becoming a CD-key/registration model, particularly where online play is concerned, rendering discs virtually useless once the key is redeemed. While this has done a lot for the legitimacy of no-CD cracks, it really sucks for the used game market, PC games in particular.
SimonG: If a pirate buys a treasure chest and buries it. Than he loses the key in a valiant battle against the british armada. Is he a pirate for picking the lock on his own treasure chest?
I once tried my hand at breaking into a car, though the car was mine and I'd locked my keys in it. While my success doesn't make me a car thief, I wouldn't be surprised if a passing cop assumed as much. Thankfully, it's easier to prove ownership of a vehicle than of a treasure chest. The cars I broke into before that, well...