Blacklisting

Blacklisting is the action of a group or authority, compiling a blacklist (or black list) of people, countries or other entities to be avoided or distrusted as being deemed unacceptable to those making the list. If someone is on a blacklist, they are seen by a government or other organization as being one of a number of people who cannot be trusted or who have done something wrong. As a verb, blacklist can mean to put an individual or entity on such a list.
Origins of the term.
The English dramatist Philip Massinger used the phrase "black list" in his 1639 tragedy "The Unnatural Combat".
After the restoration of the English monarchy brought Charles II of England to the throne in 1660, a list of regicides named those to be punished for the execution of his father. The state papers of Charles II say "If any innocent soul be found in this black list, let him not be offended at me, but consider whether some mistaken principle or interest may not have misled him to vote". 
In a 1676 history of the events leading up to the Restoration, James Heath (a supporter of Charles II) alleged that Parliament had passed an Act requiring the sale of estates, "And into this black list the Earl of Derby was now put, and other unfortunate Royalists".
Edward Gibbon wrote in "The History of the Decline and Fall of the Roman Empire" (1776) of Andronicus that "His memory was stored with a black list of the enemies and rivals, who had traduced his merit, opposed his greatness, or insulted his misfortunes".
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. The 1901 Report of the Industrial Commission stated "There was no doubt in the minds of workingmen of the existence of the blacklisting system, though it was practically impossible to obtain evidence of it." It cited a news report that in 1895 a former conductor on the Atlantic and Pacific Railroad committed suicide, having been out of work ever since a strike: "Wherever he went, the blacklist was ahead of him".
Though the National Labor Relations Act of 1935 outlawed punitive blacklists against employees who supported trade unions or criticised their employers, the practice continued in common use. The Taft-Hartley Act of 1947 made amendments which sustained blacklisting by affirming the right of employers to be anti-union, and by requiring trade union leaders to make loyalty oaths which had the same effect as the Hollywood blacklist. Since then, lawsuits for unfair dismissal have led to blacklisting being covert or informal, but it remains common.
Spanish Civil War and communists blacklisted.
At least one volunteer (George Drever) in the International Brigades who went to Spain to fight Franco's fascists and who was also well known in the British Communist Party in the 1930s was informed by the police Special Branch that his failure to progress in military or career was due to his volunteering in this cause and his beliefs.
World Wars I and II.
During World War I, the British government adopted a "blacklist" based on an Order in Council of 23 December 1915, prohibiting British subjects from trade with specified firms and individuals in neutral countries; the lists were published in the "London Gazette".
In the summer of 1940, the SS printed a secret list called "Sonderfahndungsliste G.B." ("Special Search List Great Britain") as part of Nazi Germany's preparations for invasion codenamed Operation Sea Lion – when this booklet was found after the war, it was commonly called the Black Book and described as a blacklist.
Hollywood anti-communist blacklist.
The Hollywood blacklist was 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 under assumed names for many years.
Medical context.
Blacklisting by multiple providers is a systematic act by doctors to deny care to a certain patient or patients. It is done in various ways for various reasons; blacklisting is not new. In 1907 the Transvaal Medical Union in South Africa blacklisted patients if they could not pay cash in advance. In this case, there was a physical list kept by the community of physicians. A physical list is not necessary to blacklist patients but the effect is the same.
The United States Department of Health & Human Services (HHS) found that reviewed hospitals did not generate incident reports for 93% of adverse events. The 7% of the time when they did generate reports, the information was inaccurate 63% of the time. Problems causing harm to patients were reported accurately only 2% of the time. If blacklisting is multiple providers systematically denying care to a certain patient or patients, in this case patients with iatrogenic injuries, it is reasonable to define it as blacklisting when 98% of the time the first group, treatment providers, singles out members of the second group, injured patients, to prevent them from having an accurate record made of what injured them. Those patients are further injured by not having the accurate record necessary for getting care for the injuries.
Fraud control.
Credit card merchant accounts.
Companies which have a payment card merchant account terminated, and their directors, are often added to a list referred to when companies apply for an account; they are then unlikely to be granted a new account by any provider. In the US the list is called TMF/MATCH.
Computing.
In computing, a blacklist is an access control system that denies entry to a specific list (or a defined range) of users, programs, or network addresses.