In employment, a blacklist or blacklisting refers to denying people employment for either political reasons (due to actual or suspected political affiliation), due to a history of trade union activity, or due to a history of whistleblowing, for example on safety or corruption issues. Blacklisting may be done by states (denying employment in state entities) as well as by private companies.
The first published reference to blacklisting of an employee dates from 1774. This became a significant employment issue in American mining towns and company towns, where blacklisting could mean a complete loss of livelihood for workers who went on strike.[1]