This is isn't specific to Google, and I would go further and say that ISPs are a much juicier target than Google. ISPs have the raw access to all your traffic and wilt more easily when pressed by law enforcement (eg Carnivore).

I don't think there is an easy way to solve this. From law enforcement's perspective, big tech companies have already done the hard work of getting users' data; all they need is a warrant or a NSL or any other magic ticket. That is the problem we should solve.

Disclaimer: I work on Google Analytics.