Hacking in the traditional sense(as D-SIPL can tell you) is perfectly all right - and legal.

Cracking and phreaking are both illegal and - I think they should be charged with terrorism if caught. Terrorism - vandalism - theft(of time and property).

Phreaking is stealing from the phone company and also illegal - just as bad.

Now - there's not a commandment number 11 that says
"Thou shalt not - be a cracker..."
But there is one that says "Love your neighbor." and it sure ain't loving to hack into his computer.