Google "Street View" cars collect private data should read Google "Street View" cars collect public data. (Private -vs- Public)

Apparently, the cars were recording unsecured WiFi data that was (and still is) freely available for them (and others) to receive. If you have no password on your WiFi, then it's your data we're talking about.

Unless you are using cables (or "hard wires") to connect all of your computer equipment, you are probably using WiFi. The most popular WiFi (or "wireless") technology being used is of specification 802.11 and is further classified by the notations a/b/g/n. These technologies have a specified range of at least 300 feet outdoors. This is no secret and is generally promoted on the outside of an unopened package along with other product features.

"What does all this mean?" you might ask.
Well, quite simply, if you plug up one of these radios and don't set a password, you are broadcasting your information publicly and out to anyone up to 300 feet or more away from you. You are also providing free internet access. Access that can be abused and that can result in legal action against you resulting in a lot of headache and in some cases fines of tens of thousands of dollars (fo real!).

"What can I do?" you might ask.
Set a password on your WiFi. That's it. Amazing I know. It's as simple as locking your front door. If the door is locked, no one can simply "walk right in".

"Locks are for honest people"
If I were to come across a locked door, I would not go through it. Some people, however, do not respect locks (or privacy for that matter). Just as a criminal will bypass a lock, a criminal hacker can bypass security measures. This doesn't mean you should "give up" and not lock your doors. It means you should make sure your windows are locked too and maybe get a security system. Valuable data networks should be treated with similar respect. Many companies actually pay for intentional hack attempts by "intrusion prevention service" groups who try breaking into their networks several times each year just to prove that a criminal would also fail to gain access.

To sum it up, I feel that the only reason anyone cares that Google gathered this data is because they feel that some money can be made through lawsuits. You don't do private things out in your front yard, you do them in your LOCKED area (home, bathroom, bedroom, etc.). Google drove around with a recorder turned on. They picked up some stuff. Big deal. Your neighbors are doing the same thing. Everyone has a smart phone. Everyone is taking pictures. Everyone is accessing free WiFi. Not everyone can keep a secret. Your house may be on another map somewhere that shows you have open WiFi (yes, there are actual data warehouses and maps of these). The people looking at the map may not be interested in marketing Google services. They could be looking to skim some of your free WiFi or maybe even want to camp out waiting for bank account information or other sensitive data.

We should thank Google for reminding some of us to lock our doors.