A blacklist (or black list) is a list or register of entities who, for one reason or another, are being denied a particular privilege, service, mobility, access or recognition. As a verb, to blacklist can mean to deny someone work in a particular field, or to ostracize a person from a certain social circle. The most famous systematic blacklist was the Hollywood blacklist, instituted by the House Un-American Activities Committee in 1947 to block screenwriters and other Hollywood professionals who were purported to have Communist sympathies from obtaining employment. It started by listing 151 entertainment industry professionals and lasted until 1960 when it was effectively broken by the acknowledgement that blacklisted professionals had been working anyway under assumed names.
