Well, its like saying that you should sue the police when your house got robbed instead of the robber. Scribd is the one with the intent of gaming the system, Google just wants to provide relevant search results, so its clear to me who should shoulder the blame.
no, its not clear at all, the failing is with Google for preventing what you call "gaming the system", and your analogy is flawed for the same reason. Using your analogy lets say you hire a security firm to protect your most valuable asset, then you get robbed. Who would you blame? Clearly the answer is a function of both.
However, I'm not even convinced of that Scribd have managed to game anything. Can you provide a link to google search results that backs up your claim?