"Google Sued over Defamatory Postings Found on Web Search":
Google ... is being sued by a London businessman in a landmark legal action that could hold the US-based company liable for the publication of inaccurate, malicious or damaging material on the internet.... [T]he search engine directed users to web pages that the businessman claims contained "deeply offensive and commercially damaging" material about his enterprises.
I don't know whether British libel law, which is famously much more pro-plaintiff than American law, would allow such a lawsuit. But if it does, that would spell serious trouble for any search engine that is subject to jurisdiction in Britain (for instance, because it has an office or assets there) -- and thus for users of any such search engine.