This plugin allows me to moderate comments on my blog. When I am logged in as the administrator, a "Card It!" button appears on every comment. I can click the button to issue a yellow card when someone breaches my comments policy. The yellow card prevents the post from being seen by others.
Issuing a card puts the author of the comment in the sin bin, with a tight daily comment limit. The first yellow card will impose a limit of six comments per day. The second yellow card will impose a limit of four comments per day. The third yellow card will impose a limit of two comments per day. A further breach of the comments policy will result in a red card. No comments can be posted while the red card is in force. All yellow cards will impose their limit for a period of seven days. The red card is active for 28 days.
It is possible to place a general daily limit for all blog users. This general limit is designed to encourage more considered comments.