Been busy holidayin' and doing other stuff lately, so a lot of the basic substrate of blog news and blog gossip is passing unremarked. By now, most MT users probably know that Movable Type is vulnerable as an open spam relay.
If you are not using the "mail this entry" feature, it is highly recommended that you change the permissions or the name of mt-send.cgi or both, to prevent spammers from highjacking your server to send bulk unsolicited commercial email.
If you do use the "send this entry" feature (which I had lately been thinking of adding to RFB), I don't know how you do this and keep it secure from spammers. Details as they are unearthed.
[via Mark's b-links]