Behavior is a choice, and a teacher's role is to aid students when learning to make good choices.
Inappropriate behavior is not acceptable. It should be followed by negative consequences and therefore be discouraged. When the teacher responds to different behaviors, either positive, or negative, it teaches the student something.
School is a place where students are given the opportunity to learn and receive an education as well as socialize. Part of the learning process is interaction, however, it should only occur when the time is suitable. Being in the classroom should be considered a privilege. That privilege should only be given if a student's behavior does not interfere with the ability of the teacher to teach effectively or the ability of other students to participate in classroom learning activities.
Consequences should be given to individual students who choose to interrupt the teacher's lesson or distract others. A whole class should not be punished but should be aware of how that behavior was not right.
The behavior that took place last Friday was not acceptable and should not be tolerated.