Even the great and powerful Google is limited in the number of operations and complexity of calculations in the algorithm. Many SEOs often attribute far more power and subtlety to Google's ranking criteria and filtering technology than is technologically possible, even with their recent growth to more than 100,000 servers (see NY Times Article).

Google is indeed the powerhouse of the search engines and their algorithm undoubtedly contains more than 100 and possibly even 150 major ranking criteria. However, their ability to 'spy' on SEOs, filter out SEO link-building techniques (as opposed to naturally built links) and generally confound the search optimizers of the world are greatly over-estimated.

As noted in the now-infamous Keyword Co-Occurence & Semantic Connectivity thread at SEW, just linking together ideas via keyword co-occurence is an expensive process that taxes Google's resources daily. Google may be too powerful, but the likelihood of some of the more outlandish theories about Google's ability to identify SEO tactics and penalize based on their use is still the realm of science fiction - at least for a few more years.