I have seen it two or three times. Although, I do not know if this is the case this time. People get addicted to MPNet and can't control spending (wasting?) all their time online. They ask to be volunteerily banned or suspended.
But then how would they ask to be unbanned if they're banned?
E-mail I guess. Derkrieger had himself suspended several times and finally banned. Karaahmetoglu does it and is volunteerily suspended right now. They are both on my friend list so I noticed plus they contacted the friends on their list before hand so everyone knows what is up.