The First Amendment (and the Bill of Rights) is a contract between the government of the United States and its citizens. Free speech doesn't really have a mean

The First Amendment (and the Bill of Rights) is a contract between the government of the United States and its citizens. Free speech doesn't really have a meaningful definition outside of that contract. Since you are the benevolent leader of this community you define the rules of conduct. For forums that I moderate, I am very aggressive with locking threads when even an ounce of negativity is present. I prefer to be very terse with my explanations too. I have my standard set of reasons and try not to elaborate to much. I'll finish the thread with a very terse final post. Locked: Spam. Locked: Negative. Locked: Troll. Locked: Offtopic. But this probably wouldn't scale to reddit size. People would probably try to get threads locked on purpose to quell discussion about topics they didn't agree with (especially politics).