Question: Which 2006 documentary film tells the stories of three Jehovah's witnesses who, amongst other Witness teachings, claim the right to refuse to perform military service on the grounds of freedom of religion?
Context: Military Units to Aid Production or UMAPs (Unidades Militares de Ayuda a la Producción) were agricultural labor camps operated by the Cuban government from November 1965 to July 1968 in the province of Camagüey.  The UMAP camps served as a form of alternative civilian service for Cubans who could not serve in the military due to being, conscientious objectors, Christians and other religious people, homosexuals, or political enemies of Fidel Castro or his communist revolution.  The majority of UMAP servicemen were conscientious objectors.  A small portion or about 8% to 9% of the immates were homosexual men, Jehovah's Witnesses, Seventh-day Adventists, Catholic priests and Protestant ministers, intellectuals, farmers who resisted collectivization, as well as anyone else considered "anti-social" or "counter-revolutionary."  Former Intelligence Directorate agent Norberto Fuentes estimated that of approximately 35,000 internees, 507 ended up in psychiatric wards, 72 died from torture, and 180 committed suicide.  A 1967 human rights report from the Organization of American States found that over 30,000 internees are "forced to work for free in state farms from 10 to 12 hours a day, from sunrise to sunset, seven days per week, poor alimentation with rice and spoiled food, unhealthy water, unclean plates, congested barracks, no electricity, latrines, no showers, immates are given the same treatment as political prisoners."  The report concludes that the UMAP camps’ two objectives are "facilitating free labor for the state" and "punishing young people who refuse to join communist organizations."  The Cuban government maintained that the UMAPs are not labor camps, but part of military service.  In a 2010 interview with "La Jornada", Fidel Castro admitted in response to a question about the UMAP camps that "Yes, there were moments of great injustice, great injustice!" A conscientious objector is an "individual who has claimed the right to refuse to perform military service" on the grounds of freedom of thought, conscience, or religion. Jehovah's Witnesses believe their allegiance belongs to God's Kingdom, which they view as an actual government.  They refrain from saluting the flag of any country or singing nationalistic songs, which they believe are forms of worship, although they may stand out of respect.  They also refuse to participate in military service—even when it is compulsory—and do not become involved in politics.  They believe Jesus' refusal to rule the kingdoms of the world as offered by the Devil, his refusal to be made king of Israel by the Jews, and his statements that he, his followers, and his kingdom are not part of the world, provide the bases for not being involved in politics or government.  Witnesses are taught that they should obey laws of the governments where they live unless such laws conflict with their beliefs, such as operating covertly in countries where their activities are banned. The Constitution as amended in December 2005 provides for freedom of religion; however, the law places some restrictions on the religious freedom of adherents of minority religious groups, and there were some restrictions in practice.  The Armenian (Apostolic) Church, which has formal legal status as the national church, enjoys some privileges not available to other religious groups.  Some denominations reported occasional discrimination by mid- or low-level government officials but found high-level officials to be tolerant.  Jehovah's Witnesses reported that judges sentenced them to longer prison terms for evasion of alternative military service than in the past, although the sentences were still within the range allowed by law.  Societal attitudes toward some minority religious groups were ambivalent, and there were reports of societal discrimination directed against members of these groups. Taylor v. State of Mississippi, 319 U.S. 583 (1943), was a case involving three Jehovah's Witnesses in which the Supreme Court of the United States held that criminal sanction cannot be imposed for communication that has not been shown to have been done with an evil or sinister purpose, to have advocated or incited subversive action against the nation or state, or to have threatened any clear and present danger to our institutions or our government. Conscience: Taxes for Peace Not War is an advocacy group based in the United Kingdom.  Conscience's primary aim is to change British tax law to allow conscientious objectors to military taxation to redirect the military portion of their taxes to a fund designed for international peacebuilding, conflict management, conflict prevention and other non-violent interventions.  Quakers, Mennonites, Ba'hais, Buddhists, Jehovah’s Witnesses, Seventh Day Adventists and Haredim Jews all practice conscientious objection for reasons of faith.  Many other individuals do so for reasons of conscience, some believing there is little moral difference between actually firing lethal weapons and paying someone else to do so.  Conscience believes that to deny these individuals the right to redirect the military portion of their taxes is to deny them freedom of thought, conscience, and religion as enshrined in various national and international human rights laws. Truth Be Told is a 2012 documentary about growing up in the Jehovah's Witnesses religion.  The title refers to the Jehovah's Witnesses’ perception that their beliefs are 'the truth.' Laurier Saumur (6 Feb. 1921 - 22 Mar. 2007) was born and raised Catholic, but grew disillusioned as a youth and studied the teachings of the Jehovah's Witnesses.  He was baptized as a Witness in 1944 and soon began to work as a door-to-door missionary for the Witnesses, first in Montreal and then in Quebec City.  At the time, police harassment of Witnesses was widespread in Quebec, and Mr. Saumur had been arrested 103 times for distribution of Witness literature when he decided to challenge the legal basis for the arrests. Knocking is a 2006 documentary film directed by Joel Engardio and Tom Shepard that focuses on the civil liberties fought for by Jehovah's Witnesses.  It focuses primarily on the stories of three Jehovah's Witnesses, and how their lives demonstrate three fundamental Witness teachings that have affected society in general: Conscientious objection, and rejection of blood transfusions and saluting the flag. The Fifth Amendment (Amendment V) to the United States Constitution is part of the Bill of Rights and protects individuals from being compelled to be witnesses against themselves in criminal cases.  "Pleading the Fifth" is a colloquial term for invoking the right that allows witnesses to decline to answer questions where the answers might incriminate them, and generally without having to suffer a penalty for asserting the right.  This evidentiary privilege ensures that defendants cannot be compelled to become witnesses at their own trials.  If, however, they choose to testify, they are not entitled to the right during cross-examination, where questions are relevant to their testimony on direct examination.  The Amendment requires that felonies be tried only upon indictment by a grand jury.  Federal grand juries can force people to take the witness stand, but defendants in those proceedings have Fifth Amendment privileges until they choose to answer any question.  To claim the privilege for failure to answer when being interviewed by police, the interviewee must have explicitly invoked the constitutional right when declining to answer questions.
Answer: Knocking