People are blowing this way out of proportion without realising what has actually happened.
Google did not intentionally "steal" peoples information from their unsecured networks. Google have been going around streets taking pictures. At the same time, they "sniff the air" for WiFi hotspots. The only way to do this, is to listen for packets of data.
Packets of data contain a lot of things. What Google wanted was the MAC address, or the identity, of that router. This information is contained in the packet of data. Unfortunately, as well as containing the router information, it also contained whatever data was being sent at that time, which could happen to be emails, chat conversation pieces, whatever.
All the packets are then broken down to a router address, which is also stored in a database coupled with a GPS position. The original packet is also kept, yes, but Google's statement claimed that this was a programming error, and the original packet should have been deleted.
It was a mistake is the main point!
To put it in analogy form, its like you are walking down the street, and you overhear people talking about something private to them. You heard it, you can't un-hear it. Thats that!