Thank you sir or madam, I tip my hat to you as you retreat into the shadows. I didn't post for over 600 days after creating an account here, and still like to think of myself as a lurker at heart. I am not the first to mention the idea of hiding comments from muted users, and I have also seen your idea of collapsable comment trees before. There are examples of the structure using JavaScript and DHTML. Being able to collapse and expand branches of the conversation tree might be helpful by itself; I get lost sometimes trying to remember who is responding to whom. You suggest a good additional idea that branches started by a user you have muted be collapsed by default, so you can choose to see the passive aggression. Everybody likes choice, right?