Quite a few activities could qualify for this.

On the negative side:

Spammer

Phisher

Cyberespionage

Child pornographer

Con artist (which is what all phishers and nearly all spammers would qualify as)

Blackhat hacker

Cyberthief

Cyberextortionist

Virus author

Malware author

Worm author

Jackass

Jerk

Scum of the earth

(ok, now I'm getting carried away)

Any criminal that uses a computer to commit crime is involved in cyber crime

On the positive side:

Computer forensic professional

FBI cyber division

All the military branches have groups within their criminal investigative services that specialize in cyber crime

Computer law specialist

Intellectual property specialist

Incident response

...

realize that usually careers involved with fighting cyber crime cross over several disciplines - law, forensics, network defense, etc.