A cyberextortionist is someone who uses e-mail as a vehicle for extortion. These perpetrators send a company a threatening e-mail message indicating they will expose confidential information, exploit a security flaw, or launch an attack that will compromise the company's network--- if they are not paid a sum of money.
Perpetrators of cybercrime and other intrusions fall into seven basic categories: hacker, cracker, script kiddie, corporate spy, unethical employee, cyberextortionist, and cyberterrorist.
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.