Apologies if this is inconvenient to anyone, but I've just changed the way I allow comments on this site. Usually, I allow anyone - including anonymous users - to add comments. I moderate comments on posts older than ten days, but other than that, anything goes.
Recently, I've been absolutely deluged with brainless spam comments on ancient posts... they automatically get filtered out and never actually appear on the site, but they still trigger an email and it's getting really boring. The spam comments are always anonymous, so I've now blocked anonymous comment.
Please keep adding your thoughts.... but now you'll have to use a google ID or an OpenID or something like that.
Sorry to be a pain, but hopefully that will discourage some of these spammers.
As you were.