http://www.wired.co.uk/news/archive/2012-05/03/googles-wi-fi...
That doesn't sound like very much data for a fleet of vehicles to collect over the course of a few years. Pretty sure it was just a handful of packets per (unencrypted) access point, but please correct me if I'm wrong.
http://www.wired.co.uk/news/archive/2012-05/03/googles-wi-fi...