I got shadowbanned from the entire site for years for posting a thread in two subreddits about a small indie video game I worked on for six months full time and wanted to share (in r/games and r/indiegaming, I believe).

I didn't even realize until a moderator told me they had manually approving (some of) my comments for the past six months.

I didn't submit many links but I was an active commenter, and had about 1,000 comment karma at the time.

That really sucked.