Sure, I've been banned. Three times come to mind. The two that occurred in webmaster forums involved pointing out something that was unpopular with the guy/girl in control of the ban button but were matters of fact. Banning me and removing the post was much easier than making the fact itself go away.
The first was way back around 2001, and the moderator had an ax to grind and was known to ban anyone that didnt just agree with what she said... Right or wrong. the other about 2009, and to put it bluntly the ban was a result of the site owners "roid rage". At least i hope so, itd be a shame to think he was that silly without chemical help. The topic was pretty innocuous, he was a big body builder and got pissed cause I said a well trained girl could take out an untrained stud... Size notwithstanding. Lol. He banned me on the spot, but we'd disagreed on politics previously and he could hold a grudge. He had some good points, but frequently displayed the temperament of a child.
Neither ban was appropriate, so I figured guys with serious anger issues didn't deserve my time. Never have understood the concept of returning to a place under those circumstances... Seems like a waste.
The other was on a political site. My sense of humor didn't mesh with their form of moderation. It was a temp ban, but if I'd gone back when it expired I'd clearly have run into the same issue again. When you see there's a mismatch like that, the prudent choice is move on and don't look back.