I am not sure that the capture of unencrypted traffic is actually illegal; though I will confirm that; I suspect there may be variations by state/country; I will have to read the actual laws before passing judgment on Google in this regard.
Having said that; running unencrypted wireless is a questionable practice at best. You are shouting out for anyone so equipped to hear "I'm checking my e-mail! I'm writing a response to a post on privacy! I'm surfing porn! The internet is for..." It is like expecting privacy when you are shouting into your phone on a street corner. Unfortunately there are a lot of people implementing it 'out of the box' and it was the cheapest box on the shelf.
Now, if you are using an encrypted wireless solution and someone breaks it or attempts to break it without legal authority; there is no question as to the legality.
The tech is cheap and the implementation is easy; go encrypted if you go wireless.
Having said that; running unencrypted wireless is a questionable practice at best. You are shouting out for anyone so equipped to hear "I'm checking my e-mail! I'm writing a response to a post on privacy! I'm surfing porn! The internet is for..." It is like expecting privacy when you are shouting into your phone on a street corner. Unfortunately there are a lot of people implementing it 'out of the box' and it was the cheapest box on the shelf.
Now, if you are using an encrypted wireless solution and someone breaks it or attempts to break it without legal authority; there is no question as to the legality.
The tech is cheap and the implementation is easy; go encrypted if you go wireless.