The scene where Jonah Hill punches the bathroom stall was improvised. He ended up hurting his hand, and had to go the the hospital afterward, but it ended up just being a slight bruised bone.
The fingerprint pattern on the movie poster is actually made up of the word "LIES" repeated over and over.
Sparky's Diner, located in Garnerville, New York, has been owned and operated by the same family for over 40 years. Since this film, it has been used as a shoot location for several other movies and TV shows, such as Billions, and Rise. From various angles, pictures of family members and patrons can been seen on the walls.
This movie is based on a true story.