I've been shadow-banned from a few subreddits when I was still on the site.
Not. One. Warning.
on r/images or r/gifs or something, I 'and my ax'ed on some random thread. Banned. Thread context? All deleted. No warning, no explanation, and when I asked for feedback I got something like "the ban holds" or something.
Honestly, I'm a dick a lot of the time, but I simply can't reconcile a ban for "and my ax". Ban me for the actual stuff I do, sure. A warning would be excellent. But that one bugs me the most as I can't learn from it.