This precedent sucks, but drives home how critical it is to use services that do not collect information on you.
Money quotes for the rationale:
Before a person can challenge the validity of a search warrant, he or she first must demonstrate an expectation of privacy in the area searched. In this case, we must decide whether a person who conducts general, unprotected internet searches has an expectation of privacy in the records generated by those searches. We conclude that the average search engine user—including Kurtz—does not.
For Fourth Amendment purposes, what matters is that the user is informed that Google—a third party—will collect and store that information. When the user proceeds to conduct searches with that knowledge, he or she voluntarily provides information to a third party. This express warning, in tandem with the more indirect indicators noted above, necessarily precludes a person from claiming an expectation of privacy in his or her voluntary internet use. Any such claim is not one that society would find objectively reasonable.
