There needs to be some kind of work product doctrine, which protects the privacy of routine business communication. Defining that, while allowing the collection of evidence of criminal activity, won't be easy, but the current state of affairs is unworkable.
I don't wish to facilitate corporate crime, and it's obvious that some of Google's anti-competitive behavior is unlawful. But, I don't see any realistic alternative to what Google is doing in the current legal environment.