Hackers and Crackers.
There are two words to describe computer intruders: the hacker and the cracker. A hacker is a generic term for a person who enjoys exploring and learning about computers and networks. The benign hacker is the person who does no more than to dig into his/her own computer and understand how it works. The malicious hacker is the person who gets into other people's systems for harmful or other improper purposes. The benign hackers wish that the media would stop bad-mouthing all hackers and use the term "cracker" instead. Unfortunately, this is not likely to happen and just like a lot of other technology niches, terminology will be misused and many "white hat" hackers will be tarred with the brush that malicious crackers deserve.