(I am so going to get flamed for this)
If one is blasting one's personal information out to the world unencrypted and for all to hear, then one can't complain when some third party listens to it. Google did nothing wrong - the data was in the clear.
The analogy with the car is nonsensical, Google stole nothing. Hopefully this will act as a wake-up call for people to switch their SSID off, switch to WPA-2 and use a gobble-de-gook password. And, to come back to the car thing; if one doesn't secure one's vehicles, then one might thind that they have no insurance cover - ever heard of "negligence"?
"Facebook et al...can't reveal your information if you don't sign up to their services.... Google have previously released their entire list of searches..."
Can you see your total logical disconnect? Don chuffin' use Google if that's how you feel (or use blockers/deceivers e.g. TrackMeNot, CustomizeGoogle, NoScipt, CookieCuller, Scroogle, TOR...). So it's Google's fault that you choose to use Google?
"Google is a general purpose tool and ubiquitous, it isn't a specific "social network"."
WTF? You do know that FB tries to stalk one around the net if one is retarded enough to use FB?
Gawds I must sound like a Google fanboy. Eww. But that doesn't change the facts.
1) Secure your networks people, anyone could be listening (you could even do your own PEN testing...)
2) Don't do business with people you do not trust and then bitch about it