Some comments are hidden because the account has been muted. The comments are still visible if you click on them, but if you don't like someone you can mute them and their comments won't show up in your articles comment section, unless someone clicks on them, and then they are only visible to the person clicking on them.
The negtive numbers are from someone downvoting them, who has a higher reputation score for their behavior, which the downvoter doesn't like. The downvoter can actually push your reputation number to zero or below, if they have enough hivepower and have a higher reputation number. Other people tend to stay away from those with negative reputations and mute them.
Some comments are hidden because the account has been muted. The comments are still visible if you click on them, but if you don't like someone you can mute them and their comments won't show up in your articles comment section, unless someone clicks on them, and then they are only visible to the person clicking on them.
The negtive numbers are from someone downvoting them, who has a higher reputation score for their behavior, which the downvoter doesn't like. The downvoter can actually push your reputation number to zero or below, if they have enough hivepower and have a higher reputation number. Other people tend to stay away from those with negative reputations and mute them.