It’s interesting to see this old footage of audience reaction to The Exorcist, when it debuted in 1973. Check it out:
It’s obvious that the movie caused a mini-mass-hysteria, with long lines of people waiting to get into movie theaters and reports of people fainting and running out because of the film’s graphic nature.
After the Exorcist was released, Linda Blair had death threats against her. She required body guards for 6 months.
Bonus: Here’s Linda Blair talking about the infamous crucifix scene, where she admits she didn’t understand what was going on there and why she had to stab a crucifix into a hidden box.