Google is involved in another storm in a glass of water; it is privacy again. What Google wants to know is where you are connecting from. This allows them to better target their ads.
Their cars drive by, as they drive by, they record WIFI traffic. In this way they get plenty of data to extract the IP numbers from the WIFI routers. The conversations they record are too small for anything meaningful.. Remember, it is a car driving by for crying out loud !!
If you are worried about people listening in to your WIFI traffic, use appropriate settings on your router or use an ethernet cable. Do not blame Google for what can be heard in the street by anyone anyway, that is just a red herring.