Streaming a video for use in a class, with students and faculty present in a classroom, is fair use.
Streaming a video on a Moodle website, for members of the class only, is analogous to checking the video out individually from Reserve, so this is also considered fair use.
Streaming a video at large so that anyone may view it is not fair use, and requires permission from the copyright holder, i.e., a license for public performance. Of course, if the faculty member or the student wants to show videos of her or his own work, they can give permission to do this.
See the Web Copyright Policy for more information on copyright law.