You are free to comment on my blog, but once you do, all comments belong to me and I will censor, edit, or delete at will. Play nice, and this won't happen. Honest disagreement and civil discussion are welcome, trolls, insults, and spam are not. Comments go into the moderation queue unless you've been comment-approved before. This is my site, and I decide what is acceptable.
For almost everyone who comes here, this won't even matter. I already delete the very few spam comments that get past the filters (none since the lr2spam plugin, thank you!). Haven't seen a troll since the last SonCrest post, and I left their comment untouched because it was pathetic to see. Anything I write is self-censored, this is not my private journal, or personal thoughts, I have a paper diary for those and I count this as public space.
I used to help run a message board. It was largely self-policed and unmoderated, and it worked for a while, but I will never do it again. Blogs are message boards in microcosm, each post is an author-policed board. Bloggers and commenters tend to abide by the unwritten rules: don't steal bandwidth, be nice, keep it civil and polite, offer help if you can. Comment spammers are out to steal bandwidth and search engine page rank, however they package it, however flattering the comment, it's still theft.
The First Amendment to the US Constitution says:
Amendment I - Freedom of Religion, Press, Expression. Ratified 12/15/1791.
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
The US Government cannot stop you saying anything, in theory. But there are still matters of national security that those involved cannot talk freely about. You're not allowed to shout "Fire!" in a crowded place unless there actually is a fire. Everyone censors themselves.