Search rank losses can't "be" libel. They could, theoretically, be damages caused as the result of libel. In order for something to be libelous though, it must

Search rank losses can't "be" libel. They could, theoretically, be damages caused as the result of libel. In order for something to be libelous though, it must be false, and in such a way that an average person could believe it. Satire is not libel. Writing about how you don't like Pepsi is not libel. I don't believe Pepsi could successfully sue you for expressing an opinion about their product, no matter where it ranked in Google's search results. I doubt their lawyers would even try. Of course IANAL, etc, etc.