An /r/Conservative post popped up on /r/All announcing that they would be banning anyone who shares a differing opinion, and bullshit like that. At some point in the post it said they didn't know what to call that type of community. So I quoted that bit and said,

"It's called an echo chamber. You are admitting that this is an echo chamber and is not meant for real discourse or discussion."

I was banned within 3 minutes.

I was banned from /r/Gaming for simply giving the exact version number .BIN file to use for PCSX in a thread asking on how to get PCSX working. I don't know how their no link to piracy rule applies, but that's what they used against me. The rest of the comments helping and the post itself should have also been removed and banned though, as they wanted to interpret their rules to mean any discussion of piracy or emulation. Up until the split, I had just been posting with an alt account to get around the ban.

I was banned (and later reversed) from the entire site just a month before the API bullshit announcement for making a joke about punching Nazis on a thread that was a joke about punching Nazis. I wasn't the only one, either. That entire thread got absolutely nuked by some pissed off Nazi admin. It took a week of spamming appeals before it was overturned by an admin who actually can understand context.

I was banned from... Uh... I forget the exact name of the subreddit. It was one of the Feminism subs, but it was consistently full of misandrists not actual feminists. I pointed out their hypocrisy on a thread and was promptly banned.

I was banned from /r/furry_irl for posting a trans related joke on a trans related post. The joke came directly from my sister, who is herself trans and heard the joke in her trans support group. The mods simply went "oh he's pulling the 'but I have black friends' bullshit" and then disabled me from even communicating with the mod team, labeling me a transphobe.