Which type of response from the blog owner do you think would be more likely to convince you that he was not actually an anti-Semite: 1) deleting the comment, covering up its existence, and never speaking of it, or 2) Leaving the comment in place, and refuting it - carefully laying out why the commenter is wrong.
If someone really wants to get some cheap internet points for accusing the author of antisemitism, either option can be used. In both cases, the fact that the comment was written on the blog would be interpreted as an evidence for blog somehow evoking this kind of comment. Both deleting and refuting would be interpreted like "the author pretends to disagree, for obvious PR reasons, but he cannot fool us".
The advantage of deleting the comment is that a potential accuser has smaller chance to notice it (well, unless some readers make "why did this specific comment disappear?" their topic of the month), and they cannot support their attacks with hyperlinks and screenshots. Also, if someone puts specific keywords in Google, they will not get that blog among results.
New proposed censorship policy:
Any post or comment which advocates or 'asks about' violence against sufficiently identifiable real people or groups (as opposed to aliens or hypothetical people on trolley tracks) may be deleted, along with replies that also contain the info necessary to visualize violence against real people.
Reason: Talking about such violence makes that violence more probable, and makes LW look bad; and numerous message boards across the Earth censor discussion of various subtypes of proposed criminal activity without anything bad happening to them.
More generally: Posts or comments advocating or 'asking about' violation of laws that are actually enforced against middle-class people (e.g., kidnapping, not anti-marijuana laws) may at the admins' option be censored on the grounds that it makes LW look bad and that anyone talking about a proposed crime on the Internet fails forever as a criminal (i.e., even if a proposed conspiratorial crime were in fact good, there would still be net negative expected utility from talking about it on the Internet; if it's a bad idea, promoting it conceptually by discussing it is also a bad idea; therefore and in full generality this is a low-value form of discussion).
This is not a poll, but I am asking in advance if anyone has non-obvious consequences they want to point out or policy considerations they would like to raise. In other words, the form of this discussion is not 'Do you like this?' - you probably have a different cost function from people who are held responsible for how LW looks as a whole - but rather, 'Are there any predictable consequences we didn't think of that you would like to point out, and possibly bet on with us if there's a good way to settle the bet?'
Yes, a post of this type was just recently made. I will not link to it, since this censorship policy implies that it will shortly be deleted, and reproducing the info necessary to say who was hypothetically targeted and why would be against the policy.