I forgot to check and clear down the MT activity log at the end of December. I checked it today.
Since 28 November 2004 there have been over 13,500 entries, 99% of which will be MT Blacklist blocking comment spam.
The problem is so big that, together with some image hotlinking, it's now almost doubling my bandwidth usage compared to 3 months ago.
I've emailed my hosting company to see if they can help install some scripts to deal with the problem. The scripts I want to use need some additional Perl modules installing.
I hate those guys. I can't believe you get that much though. Doubling your bandwidth? Wow.