Dave Winer have another interesting idea to deal with comment spams.
Here’s a free idea I had the other day while cleaning up a spewage of comment spam. What if comments, by default, were deleted after 24 hours? What if the owner of the site had to check a box in order for a comment not to be deleted? That way if a comment had lasting value, the owner of the site could make sure it sticks around.
Interesting..I should try to implement this in my Drupal 4 Blogger :-)