I’ve never been banned, but if I ever am it’ll be for being a jerk. 
The first time, I was banned outright after gaining administrative abilities at a board and using them to delete all threads, fora, members, et al. No email… just an account lockout.
The second time, (with the same account which had been unbanned shortly after being banned in the first place) I was emailed by the EZBoard legal department for something I didn’t even do and based on A) past history and B) my calling the twit that accused me of wrongdoing a lap dog and telling him to keep out of my affairs, I was informed by mail that I had been banned.
So, in other words, both.
A lady on another board was asking for quotes, (she was collecting them??), and she had posted a sampling of quotes she already had. They were all about kittens and eternal love and living your dreams. So I posted a quote from Bukowski’s “Best Man at a Buddhist Wedding”
“I don’t know about the bride and groom, but somebody got fucked today.”
About 10 mins. later I recieved an e-mail banning me for 30 days.
Yeah, from a certain television-oriented website that prides itself on its snark.
It’s a long story, involving an off-topic blather section that was castrated, a Meta thread, a refugee/protest message board, a favorite poster getting banned, reinstated, then banned again, then reinstated again all within a couple days for aboslutely nothing (or maybe they were just having server issues), trolling fun, a desire to go out in a blaze of glory, and a mole.
Or, some friends and I were planning a troll attack on a different message board, got ratted out, and were banned. This banning included a poster who’d been with the site from the start, posted so prolifically she was mentioned in the bloody FAQ, and only posted in our troll attack thread to mock a different poster on our message board, not that I’m bitter or anything.
Anyways, I reregistered under a different username, and went on posting about as much as I did before the banning, which is to say possibly one post a week. Oh well. Said site still sucks, though.
Err, to clarify that a bit, some people from message board B, formed as a refugee/anti-website-A board, were planning a troll attack on website A in a password-protected section of message board B. Don’t really want to name names too loudly, 'cause I like the name I have there now and being able to post my one post a week.
That Hong Kong-based messageboard that was stealing threads off SDMB. I registered and politely asked what they were doing, and they deleted all my threads and banned me.
I was banned on an Islamic message board; they had a forum specifically for non-Muslims to ask questions about Islam; there was a thread in there that was very aggressive in tone, comparing Islam to Christianity (and making some very unsound and ignorant claims in the process) - I posted once in the thread (very politely probing the factual basis of the claims) - my post was deleted and I was banned almost immediately.
Two words: Me-ow.
I haven’t actually been banned from The Kitten, but I’m not welcome back. Boo-fricking-hoo.
Oh yeah, and the people in the Madonnapower chat room don’t like me either.
That’s right, I’m one baaaad mofo.
You wanna piece 'a me? Huh? Do ya? Punk?
Only from this one.
What?
Believe it or not, for a while there in 2000-2001 the Foo Fighters Postboard was a cracking place to be - and indeed, at times it actually rivalled the SDMB in terms of it’s political and social debates - but Dave Grohl got mightily sick of the bandwidth costs (and who can blame him). He told the website administrators they would in future get a fixed budget per month (which was way smaller than what was going down at the time) and that was the deal - the messageborad could go, or it could stay but no more unlimited budget.
Imagine if the SDMB decided tomorrow that the only forum left to post in was Cafe Society and NO current events or politics were to be discussed again. Well that’s what happened to the Foo Fighters board. I suspect that more than a few folks here on the SDMB wouldn’t cope to well.
So the FF website admins decided to strip the messageboard right down to a bare bones fan club. A lot of people, including myself, had a real hard time adjusting. Gone were the juicy debates and it basically turned into a high-school popularity contest because there was so little you could talk about without getting an official warning. For some, about 5 heavy posters in particular, that decision was heaven - no longer were they out of their depth - indeed, the Foo Fighters messageboard had become the perfect popularity zone for them seeing as how nothing other than music and the Foo Fighters were all you could talk about.
Well, I would have coped OK I suspect, but there was one idiot woman who insisted on using the Foo Fighters Postboard as her own Live Journal - and the ultimate irony of course is that she actually had one and used to copy and paste between the two all the time.
Unfortunately for me, I was a big fan of the “old” messageboard and I simply didn’t cope at all with the rather sudden devolution into a messageboard which resembled nothing so much as your typical high school cafeteria with the School Prom Queen constantly asking for attention to make some new announcement each day.
My tolerance for the drama queen evaporated after a while and even though I was a long term poster who was on very good terms with a lot of the folks there - eventually I got booted.
I still lurk occasionally at FF.com just to see what it’s like nowadays and basically, it’s populated by MTV kids - and the Prom Queen is still doing her Queen of the Postboard thing. Compared to the quality of this postboard, FF.com is now a distant shadow of it’s former self.
Never been banned from a real board. Every once in a while, someone gets banned from the Something Awful forums and for some reason gets so upset they find it neccessary to start up a SA parody site, complete with boards. I’ve been banned from a few of those. There isn’t really any notification given in those cases since, by that point, they’re banning people left and right as people from the regular SA forums show up.
Apparently I have been banned from a certain feminist message board. It was more or less at my own request, although the Webmistress responded to my e-mail request that she would not ban me, but I should just stop posting. When I went back a year or so later to lurk, I found that my privileges had either been revoked or had expired.
I can’t say I miss it all that much. They do not deal at all well with anything except unquestioning agreement, and the abuse they employ instead of debate isn’t very creative.
Some of those women have some real issues, and I was allowing myself to be drawn into them in a very distasteful way. Better for everyone if I did not post there.
Hard to imagine me not fitting in on that kind of messageboard, isn’t it?
Regards,
Shodan
I got banned from a local message board called “The Party” because I made fun of someone about a Star Trek issue (he said “Warf is cool!” and I mocked him). Apparently I also disagreed with someone who had pull about the racial implications of Ben Sisko being depicted in a cage.
I got banned from AOL after complaining as a chat room volunteer that AOL was not doing enough to prevent people from coming in to gay forum chat rooms and scrolling the screen with FUCK YOU FAGGOTS DIE DIE DIE and accusing AOL of not caring about it gay customers. Our forum liaison faked TOS violations on my account (claimed I email bombed Steve Case…riiiight) and cancelled it.
-STATIC SNOW FUZZLES UP THE SCREEN-
//\/\\\////\///\///\/\\//\///\//\/\//\/
//\/\\\////\///\///\/\\//\///\//\/\//\/
//\/\\\////\///\///\/\\//\///\//\/\//\/
//\/\\\////\///\///\/\\//\///\//\/\//\/
//\/\\\////\///\///\/\\//\///\//\/\//\/
//\/\\\////\///\///\/\\//\///\//\/\//\/\
eruption e eruption
r r eruption
u u eruption
p p eruption
t t eruption
i i eruption
o o eruption
n n eruption
A PERSON APPEARS IT LOOKS LIKE THEY ASRE SNUFFLING ABOUT OUTSIDE, CLOSE TO A WELL OR SOMETHING, REPORTS THAT THE WELL IS MADE OF SPAM ARE AT THIS MOMENT UNCONFIRMED
-WHITE SNOW-
//\/\\\////\///\///\/\\//\///\//\/\//\/
//\/\\\////\///\///\/\\//\///\//\/\//\/
//\/\\\////\///\///\/\\//\///\//\/\//\/
//\/\\\////\///\///\/\\//\///\//\/\//\/
//\/\\\////\///\///\/\\//\///\//\/\//\/
//\/\\\////\///\///\/\\//\///\//\/\//\/\
THE TAPE ENDS
the phone starts to ring BRRRNNNG BRRRRNNG
I once posted that in a forum and kept refreshing it once itwas posted, then I had written down most of the names of the people who looked at it and sent them a PM saying something along the lines of " I know you looked at the tape, you will die in 7 days"
I thought it would be fun, it was my idea of an interactive posting experiment, I thought it was art man. I got banned.
Luckily I had my other user-name so I could get back on and fight my case. I was back on in smam form within a day or two.
Hee hee smam, that’s genius.
I was banned from Fulham FC MB.
Well they got on my nerves telling me what a big club they were so I gave 'em a few home truths and I didn’t even use bad language, well maybe a little 
I got banned from the Democratic Underground twice. I have now gone to running myself through other peoples offical e-mail address…
I am banned from Fathom, but not for anything I actually did or anything. Just on those few random occasions I’ve tried to look at it, out of curiousity, it says I’m banned. Since I’m getting internet access through my school, I assume I’m thus in a banned IP range due to some jerk who happened to be a student here as well.
It occurs to me that instead of getting bored with the snopes boards and just drifting away, I should have had some fun and gotten banned instead. Oh well.
Larry Mudd, I would’ve appreciated a warning about the content of that first photo you linked, though to be fair, you did mention “the gory parts.”
shudder
I was banned from a now-defunct Diablo message board called the “Lurker Lounge”. It’s mods were infamously known for being excessively totalitarian in nature. I don’t remember why I was banned, but it was probably because I did something they didn’t like (I didn’t know why they did it then, and I still don’t know now). They were known for banning people who didn’t give the board the impression they wanted.