Around 20 hours ago, I made a comment on this answer. The entire text of my comment was:
Congratulations! You helped create the Silk Road :-). http://krebsonsecurity.com/wp-content/uploads/2013/10/UlbrichtCriminalComplaint.pdf
Could someone kindly tell me which moderator deleted my comment, and provide a link to the written policy he or she was enforcing?
I made my comment hours before the question was protected, and it was present hours afterward. The last time I checked, it had over 20 upvotes and a good, funny reply from the answer's author. My comment is not racist, sexist, ad hominem, nor offensive to anybody, except in the sense that every statement whatsoever is offensive to "somebody".
Again, my comment was not one of thousands; it was one of two present before the post was protected. And it was there for hours afterward, so the moderator who protected the post did not see a need to delete my comment.
[Update]
This Meta-FAQ says (emphasis mine):
Comments that are flagged by multiple users are deleted automatically. The number of flags needed is based on the comment's score. It currently takes "3 + (Score / 3)" flags to delete a comment.
...
Generally, there is very little reason to delete existing comments from a question or an answer. There are a few possible scenarios where comments ought to be deleted, but it is worth noting that these should be few and far between, due to their permanent effect on the flow of the comment section.
So there is a formula for weighting the community's judgment about the relevance / "noisiness" of a comment. If every moderator substituted his/her own judgment for that of the community, deletions would hardly be "few and far between".
Heck, we have an answer right here that thinks the author responded enthusiastically (rather than just, say, flagging my comment) just to "play along".
My comment had enough eyeballs and upvotes that the community clearly had made a judgment. If my comment was deleted by the automatic formula, fine! If it was deleted by some overactive moderator who thinks he/she knows better than the community what "noise" is... not so fine.
StackOverflow is a Q&A site, but it is also a community. There is a huge difference between the community voting to delete a comment and a moderator substituting his/her own judgment to do so. It is the difference between a "consensus" and an "authoritarian" system.
Can I tell which one this was? Or is that a feature request?
[Update 2]
One more quote from the Meta-FAQ (again, emphasis mine):
Comments exist so that users can talk about questions and answers without posting new answers that do not actually answer their parent questions. Comments are often used to ask for clarification on, suggest corrections to and provide meta-information about posts.
You folks might want to update that Meta-FAQ, since it clearly says the opposite of what most of you are saying.
I guess I have my answer about "consensus" vs. "authoritarian".
[Final Update]
First, this question is obviously not a duplicate of the FAQ, so I request that it not be marked as such. I asked a direct question about the comment moderation policy (clearly on-topic for Meta) and requested references. When I got the reference to the FAQ, I incorporated it into this question and pointed out how deleting my particular comment appears to be inconsistent with what is described by the FAQ.
Second, moderators have censorship power, and such power should always be exercised with restraint, in my opinion. (One might say the applicable cases should be "few and far between", to coin a phrase.) The concept of "on-topic" is subjective; everyone will see it differently. Moderators should err slightly on the side of free expression, and very much on the side of deference to the community's opinion. In short, upvotes should matter. They are not the only thing that should matter, but they should matter.
Contrast this with the accepted answer to this question, where Robert Harvey explains his policy is to delete anything that does not serve "the purpose of comments", in his sole opinion, regardless of votes. I consider this policy ham-fisted, authoritarian, and the exact opposite of the attitude a good moderator would have... But, apparently, this is the actual policy, so I suggest stating it clearly somewhere.
Finally, I do not think the responses here indicate anything about the general SO community. They do indicate quite a lot about the community that hangs out on Meta. On the real SO, no on-topic, clear, civil question would receive 40 downvotes.