Known as being one of, if not THE scariest horror movie ever made, The Exorcist is one of those films that, like 1971's The Godfather, has aged incredibly well, and still startles audiences in this day and age. Most people can remember the first time they saw this groundbreaking film, and likely spent the whole night laying awake, unable to sleep. Although in terms of gore and violence that we're so used to seeing in modern day horror flicks, The Exorcist remains terrifying, without using gratuitous violence.
The video below shows the genuine reacts from theatre goers in 1973 (the year of the films release), and you can tell just how much of an impact it made on these people 42 years ago. Cases include (although not shown in the video) people throwing up, fainting, and leaving the cinema, as they simply could not handle the film's content. One man even broke his jaw on the back of a seat when he fainted, and sued Warner Brothers... he actually won the case and received an undisclosed sum.