regular users of GFS (developers) couldn't trivially access that data, but certainly up to a point it was possible for expert users to troll that data (if you were caught, you'd be fired). Eventually better protections were applied.

I worked with a guy who had built part of search and later made the gmail "lawyer search" feature (legal discovery). He said that any interest in looking at people's emails went away after having to spend hours going over various emails involved in court cases (typically done in a room with several lawyers) to make sure the ranking algorithms could surface emails demonstrating illegal behavior