I recall that the Shoutbox, in it's first weeks of inception, was abused and spammed to hell. The Admins quickly decided to reset it, and put a little grey (green?) message above it, warning those that use it that the shoutbox was a "little to zero tolerance zone", and that infractors would be permanently restricted from using it.
It seems that in the moving here and there of the forum this message disappeared, but it seeped into the minds of the community that the shoutbox banhammer was lightning fast.
Until one guy who decided to come back one day and was not aware of this committed the offense, and decided to call foul. For he was not properly informed.
Informed that civility has perks, and lack of temper has penalties.
TL: DR bring back the shoutbox disclaimer that warns people to behave.