I have recently gotten calls and emails from artists on Stencil Archive who were perplexed at the huge amount of comment spam that was accumulating on the Archives (Gallery in Drupal-speak). As I discussed things with my web admin, I watched the comment spam go from 900 to 1300 in a matter of days!
I just had the admin wipe all the comments from the Gallery Module (sorry, it had to be done), and I just set up Captcha, a module that makes people enter numbers when they leave comments (spambots cannot do this). Hopefully this will stop the problem (or at least slow it down until the spam-lords find a workaround).
Captcha is also set up for the comments on the other part of Stencil Archive (the post comments). Not much spam action there but now it is protected.