Anyone that was running a open wireless connection should be very happy it was only google that stole their info. If they wanted to do bad things they sure would not have admitted it.
Sounds like they ran one of the wireless sniffers and captured anything in the air trying to find open access points. It does not sound like they attempted to break even the simple to break WEP only captured what was open.
Even if you look at their stated goal and if they didn't capture any private data you have to wonder. Creating lists of lazy people who do not protect themselves is almost like someone who would check doors and list who left them unlocked. Still stupid people need to take some responsibility for themselves.
Google's Wi-Fi Spying: What Were They Thinking??