Library Research Guide
Section 110(1) of US Copyright Law permits the performance and display of legally licensed/purchased works protected by copyright for education purposes in nonprofit educational institutions.
17 USC 110(1)
(1) performance or display of a work by instructors or pupils in the course of face-to-face teaching activities of a nonprofit educational institution, in a classroom or similar place devoted to instruction, unless, in the case of a motion picture or other audiovisual work, the performance, or the display of individual images, is given by means of a copy that was not lawfully made under this title, and that the person responsible for the performance knew or had reason to believe was not lawfully made;
If a movie has an instructional purpose related to the course and it's only being shown to students enrolled in the course instructors in a face-to-face class may use content appropriately.
For more information see the ALA Copyright and Video Guide.