Praise be to Allah.
Watching movies includes looking at things that are haraam, such as seeing ‘awrahs, following immoral actions, or listening to things that are haraam such as music and obscene talk. Undoubtedly it is haraam to watch them in this case.
If the movies are free of such things, then there is nothing wrong with watching them, so long as that does not distract one from remembering Allaah or keep one from doing something that is obligatory.
No distinction is made between documentaries and other kinds of movies.
Watching movies has a bad effect on the individual and on the ummah. These include the following:
1-Provocation of desires
2-Propagation of immorality which is made attractive and easily accessible
3-Teaching and justification of crime, and making it familiar to young and old
4-Corruption of married life, by making the wife seem ugly to the husband and vice versa, by showing images of attractive girls and men
5-Spreading corrupt beliefs which are based on kaafir theories, such as the theory of evolution, or attributing the powers of creation and destruction to researchers and inventors, or propagating magic, soothsaying and claims to know the unseen, or making fun of religion and religious people, and other things which appear in movies that are shown to young and old.
6-Wasting time and draining away energy, living with illusions far removed from reality.
And there are other evil consequences.
Shaykh Ibn Jibreen (may Allaah preserve him) said: Another of the evils of looking at those beguiling images and enjoying watching them is those images which are shown in movies on videos and on the TV etc, which show images of adorned women, especially those which are broadcast from foreign countries, and those that are shown via satellite, etc.
They are a fitnah (trial, temptation), and what a fitnah. The one who looks at those images cannot be sure that he will remain uninfluenced by the image of this woman or this zaani (adulterer) or this one who is committing evil and showing him the way to do it. He may not be able to control himself and stop himself from looking for ways to fulfil his desire, if he does not have the faith to stop him looking at these images, whether they are drawings, photographs in the pages of newspapers and magazines, or they are shown in direct broadcasts or in movies and the like.
These sins and haraam things are prevalent everywhere, and they are calling people to commit immoral actions. When a woman watches these non-mahram men, she cannot be sure that her heart will not incline towards committing immoral deeds, and when a woman sees these immoral, adorned women she would be temped to imitate them because she will think that they are smarter and stronger than her. That will make her cast aside the garment of modesty and uncover her face, and she will show her beauty to strangers, and she will become a fitnah and what a fitnah. End quote from the website of Shaykh Ibn Jibreen.
For more information on the dangers of TV, see the essay al-Ijhaaz ‘ala al-Tilfaaz by Shaykh Muhammad Ahmad Ismaa’eel.
See also questions no. 3633, 3324, 1107, 13003 for the rulings on watching TV and movies.
And Allaah knows best.