The only justification for our concepts and systems of concepts is that they serve to represent the complex of our experiences; beyond this they have no legitimacy.
Who Is Threatening Your Data?
Blackhats. Crackers. Hackers. Script kiddies. Bad guys. Cyber terrorists. Agents of information espionage. Those are some of the many names that the media and the computer industry at large have given to individuals who attempts unauthorized access or use of your computing infrastructure.
Regardless of their designs, we'll call anyone breaking into your system an "intruder" and anyone who is trying to get in an "attacker." Most commonly, attacks come from within, from current or former employees.