The Teddy Bear Master (2006)
The Teddy Bear Master is a 2006 American film produced by a group of High School students which depicts a teacher being harassed by teddy bears during class, then later being killed by them, after he humiliates a student. The 78-minute film attracted international attention when it became the subject of two separate legal actions, firstly after the school expelled the students involved, then later when a maths teacher who shared the surname of the teacher in the film sued the producers for provoking "reasonably foreseeable emotional disturbance or trauma".
More at Wikipedia.