What's the difference between a hacker and a cracker ?

Lets get this question out of the way right now:

On USENET, calling someone a "cracker" is an unambiguous statement that
some person persistently gets his/her kicks from breaking from into
other peoples computer systems, for a variety of reasons.  S/He may pose
some weak justification for doing this, usually along the lines of
"because it's possible", but most probably does it for the "buzz" of
doing something which is illicit/illegal, and to gain status amongst a
peer group.

Particularly antisocial crackers have a vandalistic streak, and delete
filestores, crash machines, and trash running processes in pursuit of
their "kicks".

The term is also widely used to describe a person who breaks copy
protection software in microcomputer applications software in order to
keep or distribute free copies.

On USENET, calling someone a "hacker" is usually a statement that said
person holds a great deal of knowledge and expertise in the field of
computing, and is someone who is capable of exercising this expertise
with great finesse.  For a more detailed definition, readers are
referred to the Jargon File [Raymond].

In the "real world", various media people have taken the word "hacker"
and coerced it into meaning the same as "cracker" - this usage
occasionally appears on USENET, with disastrous and confusing results.

Posters to the security newsgroups should note that they currently risk
a great deal of flamage if they use the word "hacker" in place of
"cracker" in their articles.

NB: nowhere in the above do I say that crackers cannot be true hackers.
It's just that I don't say that they are...