[hotcool]

My comments on HN get shadowbanned for no discernable reason. Does that count?

[kelukelugames]

HN has shadowban?

[vonmoltke]

Sort of. There is a mechanism to "kill" a user's posts; these are posts that get flagged "[dead]". A logged-in user with showdead checked in their profile can still see them, though. In fact, as of several months ago users can "vouch" for dead posts that should not be dead.

[hotcool]

Comments are shadowbanned too. Just log off on your account and then check your comments and submissions. Are they still all there?