'cracker' has been used in this context since at least as far back as my first computer, an Amiga 500. I got a lot of games from a bloke called "Norm the Cracker"...

Hmm. I've always taken the recent hacker/cracker as the following:

Hacker: One who breaks into computer systems or networks one does not control or have access to.

Cracker: One who breaks into software and firmware on their devices as to gain control of root over their machines. This may be in contention with the arbitrary licenses they may have agreed to prior to installation or purchase.

I bet kittihawk is talking about the usage of cracker as a derogatory term as it regards to white people: https://en.wikipedia.org/wiki/Cracker_(pejorative)

Crackers has been the term for decades. Have you never read the jargon file?

http://www.catb.org/jargon/html/C/cracker.html