If I connect my laptop to your Wifi network because you do not have a password, is that connection authorised without you saying I can do it?
If I connect my laptop to your Wifi network because I know your network password (lets say I guess it), is that connection authorised without you saying I can do it?
If I create a "guest" login on a web server that has no password and someone logs into it without my authorisiation, is that against the law or not?
If that "guest" login also has "guest" as a password and a hacker guesses both and logs in without my authorisation, is that against the law or not?
The correct answer to all four of these questions is "no." Accessing a private resource that you have not been given prior authorisation to access is effectively trespassing. Think of it like someone walking onto your property because you don't have a fence. Whilst it maybe careless and inviting trouble, in no instance does that recklessness on the part of the owner give others the right to do what they choose.
Just because the radio data is being broadcast and you can receive it, you are not automatically entitled to access or use hardware that is transmitting it or connected to the transmitter. Consider that when you connect to a wireless network that you are communicating with a wireless access point, not just receiving its data, and thereafter sending data to that network.
It has already been admitted by Google that they received data from wireless networks that in turn required them to actually connect to those wireless networks.
In actual fact, there is only one possible outcome in every case where a government is investigating at that is for Google to be found guilty. If anything else happens then it could be argued that not even encrypted data is private. The question isn't about what form the data takes but whether a 3rd party has a right to access it without authorisation.
Lets say that I collect a month of your encrypted wifi data and then break all of your encryption keys. I then post it all over the web. The data was broadcast over the airwaves, therefore it was public. That it was encrypted was just you believing, foolishly, that the data was private and therefore unable to be accessed by others. How would you feel about that? Whether or not the data is encrypted is beside the point - you're broadcasting it to everyone within about 100', so why should you have any right to privacy as a result of that broadcasting? If you want your encrypted data to be private then data that is not encrypted must also be private. Electromagnetic waves have no specific property that says "I'm private" or "I'm encrypted". The presence (or lack thereof) of encryption is not a representation of whether or not something is or should be private. Start by accepting that all privately transmitted radio data is private unless you're specifically broadcasting for public benefit.