My understanding is that trade secrets are distinct from patents. For patents, you tell everyone how to do it but they're not allowed to for 20 years. For trade secrets, you don't tell anyone how to do it, but if someone else figures it out for themselves, it's fair game. Most of Google's search IP is protected as trade secrets rather than patent/copyright, I believe.

Your point is that you can't copy Google's secrets because of copyright, and therefore copyright is valuable to its employees. I'm saying that the reason you can't copy that information is different from copyright.