The practice of banning an individual from a job or entire field. This is usually implemented as an industry wide tactic, exiling a particular individual due to public beliefs or supports. This was infamously practiced during the McCarthy era, often ruining careers permanently.
Another culture influenced definition for blacklisting is to ban an individual from going onto flights. "Blacklisted" individuals are put on permanent "no flight" status throughout nearly all major airlines. Many are listed due to suspected terrorist status listed by the United States government. Or someone like Julian Assange, who is wanted by Interpol, and would be denied access to leaving a country that is investigating him.
History While the definitive history of the term is debated, the concept has been used throughout history for many major moments. For example, the Catholic Church used (and officially still could) the practice of "excommunication" to ban individuals from their Church organization, and effectively sent them into exile from nations, essentially banning them from society. Another big example was the blacklisting of Jews during Germany's rule under the Nazi Party from 1933 to 1945. Anyone of Jewish descent was banned from employment and partaking in anything within the German society.
The most famous example of this term was the period during the 1940s and 1950s within US culture when the Red Scare was the dominant political issue. Anyone who was even accused of Communist activity and political activism was blacklisted, and most who recognized the bla cklist would not employ and essentially force the individual into a sort of exile. Hollywood was notorious for instantaneously blacklisting anyone (ranging from actors, directors, writers, etc) who gained even an inkling of suspicion from the government (or civilians in general).
Examples of Use
Outright enforced blacklistings are not as common today, but are still used through subtle social and political pressures. The most current example of this would be the blacklisting of Julian Assange and the Wikileaks organization. The US government has effectively pressured companies and world communities by urging them to stop doing buisness with them or enabling them to do so. Credit companies and server hosts (like Amazon) have been pressured by the US government from doing buisness with them, essentially blacklisting the organization.
The press and media were effectively used during the Red Scare era to communicate blacklistings and communist suspicions, even if they weren't true and groundless. While not as literal as outright banning someone from an institution, the media has also blacklisted individuals from their own communities, in a sense, by reporting pieces that may not be immediately true. Alligations are dangerous to make, as simple claims going public is enough to ruin someone's life. There may even be quiet suspicion that whiteblowers are doomed to blacklisting for vocalizing the truth about illegal operations.