In computer security, a hacker is a person who specializes in work with the security mechanisms for computer and network systems. The subculture around such hackers is termed network hacker subculture, hacker scene or computer underground. While including those who endeavor to strengthen such mechanisms, it is more often used by the mass media and popular culture to refer to those who seek access despite these security measures. Accordingly, the term bears strong connotations that may be favorable or pejorative.
The network hacker subculture initially developed in the context of phreaking during the 1960s and the microcomputer BBS scene of the 1980s. It is implicated with 2600: The Hacker Quarterly and the alt.2600 newsgroup.
By 1983, hacking in the sense of breaking computer security had already been in use as computer jargon, but there was no public awareness about such activities. However, the release of the movie WarGames that year raised the public belief that computer security hackers (especially teenagers) could be a threat to national security. This concern became real when a gang of teenage hackers in Milwaukee, Wisconsin known as The 414s broke into computer systems throughout the United States and Canada, including those of Los Alamos National Laboratory, Sloan-Kettering Cancer Center and Security Pacific Bank. The case quickly grew media attention, and 17-year-old Neal Patrick emerged as the spokesman for the gang, including a cover story in Newsweek entitled “Beware: Hackers at play”, with Patrick’s photograph on the cover.  The Newsweek article appears to be the first use of the word hacker by the mainstream media in the pejorative sense.
As a result of news coverage, congressman Dan Glickman called for an investigation and new laws about computer hacking.  Neal Patrick testified before the U.S. House of Representatives on September 26, 1983 about the dangers of computer hacking, and six bills concerning computer crime were introduced in the House that year.  As a result of these laws against computer criminality, white hat, grey hat and black hat hackers try to distinguish themselves from each other, depending on the legality of their activities.
Filed under: Hack Trick