I you think about it, the only reason to get banned from a publicly available site should only be related to profane or abusive language or (maybe) posting consistently off-topic (but most on-line groups have a place to do that).
I've founded and moderated a couple of successful (and on-going) groups and have been invoved in many for several years. The best and most active of the groups have always shared in common a "no rules, just be nice" philosophy; the groups are essentially self-regulating; the moderator/owner/manager only steps in to git rid of spam. Things that stretch the limits are usually dealt with in private emails between the moderator and offender and not made a public spectacle.
In my (maybe not so humble) opinion a moderator/owner/manager that excercises his/her "powers" publicly on the group's message board is more into inflating his/her own ego and establishing a "kingdom"; it's not really about having an open, self-regulating group that functions without much interference. Peer pressure is awesome and carries much more weight that one person (even if it is the owner of the group) "yelling loudly" in publicly displayed messages.
Anyone starting a group to which any member of the on-line public can join, without invitation and without qualification must realize that the group will be composed of a broad cross-section of the public and therefore embrace many personalities, even if all share a common interest in the group's reason for being. If one wants a kingdom (or dictatorship) that group ought to be a closed group joined only by approval or invitation; at least that way the person joining knows what rules one is going to live by.
I didn't get banned from the other site (probably only a matter of time if I had stayed; not because of anything I said but rather because of what I would have said) but choose to leave and come here when faced with the abusive nature of that group's owner. This is so much nicer!