One lesson I have learned is never engage an (on-line) student immediately after he/she has done something antagonistic in front of the class. All it takes is on bad episode to spiral out of control as from a on-line facilitation perspective, it is extremely tough to put the genie back in the bottle again :-) My recommendation (if this occurs in an online class): (1) Whatever response you make, ensure you had ample time to think about both the content and medium (2) Go private - Resist the temptation to let everyone know who is the boss