We're changing our site policy slightly with respect to anonymous comments.
Since it's very easy to be rude when hiding behind an anonymous account, site policy from here onward will be to delete anonymous comments that we find impolite or trollish. There's been a debate for a long time about whether to allow them at all, and we've decided in the past that there are a lot of anonymous users who add value to the site with their comments, and I don't want to force those people to register. As the site grows, we may need to reevaluate that, but for the time being anonymous comments will be allowed.
Please note that I can't be in the business of policing every single comment to reach the site. If I miss a rude comment by an anonymous user, please contact me through the contact form and leave a link to the page with the offending comment, and I'll take care of it.