Every couple of weeks I hit the admin pages of UrbanPotato and delete around fifty spam comments. My spam ritual tonight left me with a surprise: navigating to the comment admin pages took the site down with 100% CPU and many hundreds of megs of cache consumed by SQL server. After restarting the site, I checked the comment tables in SQL server and, since 1/1/2007, over 48,000 comments have been added to the site.
Yes, I could use one of the many captcha methods that try to prevent spam bots. I could require registration. But in the end I decided that it's just not worth my time, or the time of people who visit. I do have a day job after all, and so do you.
I have disabled all comments and referral links on the site and deleted all comment records and referral statistics from the database. It's now a closed system. Spam bots will need to go somewhere else.