[ars]

No, that's not from downvotes, that's from "flagging".

Personally I only flag spam and hate speech, but some people get really upset by certain posts and will flag them rather than (or in addition to) downvoting.

With enough flags the post becomes "dead" and then you can't reply to it, and it's hidden by default. It's possible to un-flag it with the "vouch" option.

I think flagged posts are often reviewed by dang (a moderator).