Thread: Not a 'Fit and Proper Person'

Reading back through some older threads, I came across one started by 'pepper 123' on 21-5-2017 titled 'Brass damage ?? Help'
Forum readers gave the normal balanced and helpful advice feedback as usual.
Pepper 123, without any provocation lost his temper and launched an aggressive swearing tirade against forum members.
I am not a phycologist, but life experience tells me that pepper's reaction was not in the 'normal area of the 'Bell curve' Have a read, in short the guy can only be described as a Nutter with an uncontrollable temper. Pepper is not someone who should be allowed to own firearms.
Has this type of situation been faced before and how do we deal with it ?