On July 20, 1969 Neil Armstrong and Buzz Aldrin became the first men to step foot on the moon. Almost immediately conspiracy theorist began to cultivate the idea the mission and the five successive ones were hoaxed in order to give the US a major public relations boost near the height of the Cold War. These theorist point to many supposed inconsistencies and inaccuracies in the NASA footage for the moon landings, and that the technology was simple not available at the time to actually pull off the feat.
Once of the major points of contention that conspiracy theorist like to attack is flag blowing in the wind. They claim that since the moon is a vacuum and there is no atmosphere it should not shift in the way it does when planted. However, these proponents fail to use the Scientific Principle of Replicabity. If you actually place an exact copy of the flag planted on the moon in a vacuum and 'plant it', it will behave in the exact manner shown in the NASA footage.
Another point of contention in the eyes of conspiracy theorists is the fact that the NASA film of the astronauts appear to be slowed down to produce the desired effect of running in 1/6th moon gravity. Again, these proponents fail to utilize the scientific principle of Replicability. Scientist have replicated the movement of the astronauts using zero gravity plane ride simulations.