Also, Google notes that they will start offering an encrypted version of Google Search starting next week.

Alan Eustace, Senior VP, Engineering & Research, posted some bad news for privacy advocates today on Google’s Official Blog.
Those cars (right) that go around collecting images for street view use local Wifi hotspots to help map the world. It turns out that they’ve also been collecting and storing data from those unsecured hotspots. Anything that was being transmitted during the time those cars were driving by may have been picked up by Google’s software and stored.
Should we be worried about this? Not really. That same data could be collected by anyone with some free software. It is one of the hazards of having an open Wifi router. That’s also why when you do important things like banking, you use a more secure protocol, https, whose transmissions can’t easily be intercepted, even over unencrypted channels.
It also seems that it was an honest mistake on Google’s part.
Google says it will work with local authorities to show what information was collected and make sure it is disposed of properly.
In a mostly unrelated matter, Google said they’d begin offering an encrypted version of their search engine next week.