It seems that I am starting to get hit with comment spammers. My site is rated fairly high on Google, as there aren't many sites out there about Nuclear Moose. I have comment moderation on, so at least they don't get posted.
Today I decided to kick up a fuss. I ran the whois and stuff and sent the following note:
It is my policy to bill US$150.00 for every unsolicited advertisement placed on my site. I give a single warning and then I start sending out invoices. Please advise your client of this. If I am unable to bill the client directly, I will bill the client's Internet Service Provider for failing to enforce acceptable use policies.
Thank you for your attention to this matter.
Can't wait to see the response!