Google's view of the world is just opinion

The Google-opoly of page rank is just their opinion, nothing more, they can change it at any time, it came up in court and looks likely to remain that way. From slate:

A terrific analysis of the case from James Grimmelmann on LawMeme suggests that Google is more than just sorting Internet content: It's a "gatekeeper" that effectively bars access to anything ranked lower than 200 by its ranking system. Massa seems to commit legal hara-kiri on his Web site by conceding that Google's opinions are protected by the First Amendment.

If your page rank changes over night, and the gatekeeper decides to close the gate for what ever reason, there is nothing you can do, in Google we trust, but I guess they know that.