We take a ban very seriously here, it's never just an emotional response to someone acting stupidly. A ban is used to protect the membership from a predatory or dangerous individual.
Or if someone is a troublemaker and WILL NOT listen to guidance by the Mods, or refuses to obey the forum rules, then we remove him. In those instances we will ban only after warning the individual many times. In some instances the member will be suspended for a couple weeks to "give them another chance". Usually that works.
Usually a ban is permanent, but there were odd exceptions. Over the last few years one person was banned and managed to sneak back in TWICE under new usernames (note I'm talking about someone else, not "Bluetack"). We knew it was him, and seeing much improved behavior, we let it slide each time.
Unfortunately, that person screwed up again, and was banned again. Some people just have a really hard time following the rules, and as we are all volunteers here, eventually the mods/admin staff get tired of dealing with the same behavior over and over and over. I have extended an olive branch to this individual (the other guy, not "Bluetack") but now he's playing coy, so I'm thinking this will be another permanent ban.
We take no pleasure in banning people. We exhaust our options before resorting to that.