From the Webmasters committee:
Users of the transformativeworks.org news blog have reported seeing an “access denied” message when attempting to unsubscribe from comment notifications. This unfortunately coincides with a large influx of spam comments, which is resulting in lots of unwanted e-mails for users who are subscribed to notifications. To protect our users’ inboxes from further spam, we have temporarily disabled comment notification e-mails while we work on the problem. We will post an announcement when notifications become active again.
This applies only to posts on transformativeworks.org; comment notifications on our Dreamwidth and LiveJournal mirrors are unaffected.