I was browsing the web, looking to see how others were dealing with the problem when I came across this post on a discussion board.  The writer mentions that the sudden rise in spam corresponds to the start Spamhaus' legal troubles.

If this is true (and I'd have to check our historical data to verify this), then we all know who we can thank for this latest onslaught of spam.  I'm not going to mention this company's name that is suing Spamhaus, but if they are responsible for this rise in spam then the rest of us have good reason to be annoyed at them.

And by annoyed, I mean very angry.