I'll venture the guess that words cannot describe how fucking stupid that post was. He got off light with 8 months.
It's much more like leaving their corpse hanging and rotting for all to see. The purpose of banning is not to legislate opinions, no matter how stupid. It's to keep the conversations that would inevitably ensue out of here. Preserving the crime scene as a warning to others is a good way to do that. A lot of people can seem to figure out for themselves where to draw the line. So that gives them a reference point.
5 to 10 years if I remember right. I like the older version of the BBS and the banning options. You could give people anything from an hour up to decades.
There's also the whole putting heads on spikes thing, not sure if it has a specific term. I only know the gibbeting one because I read it in a book recently