call for help

I need a bit of assistance from my fellow webmasters. My bandwidth is being hammered for some reason. I’d like to blame it on the popularity of my site, especially with the recent influx of the Hootie commenting variety, but there is nothing bandwidth intensive about those posts, and I noticed quite a spike before I even posted about that. I’m pretty certain is has to do with the scourge of the internet – comment and referer spam, but I’m just having some trouble tracking it down and coming up with a good solid defense plan.

  • January – 656MB
  • February – 2.18GB Yes, that’s Gigabytes Charlie Brown
  • Today – 50MB

Any ideas anyone? I already have drDave’s Referer Karma in place – but from looking at my stats – it’s not working.