Sad Thing

I've had to delete six comments this morning alone which I believe to be the work of spammers. I have added the offending addresses to a banned list.

I assume the list will be largely ineffective... but I'm finding that I'm going to have to be vigilant now.

I wonder if Typepad has implemented anything or can implement anything similar to the MT Blacklist plugin? And I wonder if it would even be effective against attacks like these.

Other alternatives are to allow commenting only for registered users, or to allow no commenting or trackback pings at all.

Advice?

Anyone?

Thoughts?