Some of this discussion is a bit silly. Don’t misunderstand me, a time-based response or random response makes it more difficult to determine how the black box works. IMHO, this is what the patent is really about.
Google doesn’t need to shake the bushes to find the overly optimized sites. It’s as simple as this: build a relationship between G+, GA and GWT accounts and websites. Build a list of scummy SEOs (e.g. the ones with the ‘Gold’ package -- building 800 inbound links a month, 20 new pages, and 6 micro sites). Marry the accounts/websites to the SEOs. Bingo. Done! You’ve got a list of websites likely using bad SEO techniques. Guilt by association. Okay, go the extra step and validate it. Penalize them all and bleed-out the SEOs.