No, it’s not illegal, and lots of people do it. If you don’t secure it, then it’s open and your computer without modification will connect to it and use it. Nowhere near illegal, tht’s just something that old people and full of themselves say. Why not help people secure their networks if they care instead of making stuff up.
Unauthorized access of a computer network is illegal in the State of California. People have already been arrested in other states for doing it, only a matter of time before it happens here, see:
Doesn’t matter whether its secured or not. If the owner of the network has not *explicitly* granted you permission to use it you are breaking the law. I’m not suggesting this law makes sense or is easily enforceable for wireless networks, but it is indeed the law.
Think of it like a house. If someone leaves their front door open while away and you walk in and use their bathroom, you can still be arrested for trespassing. The fact that the homeowner is negligent is no matter.
I already have a full-time job securing networks (including WiFi ones), thanks for the advice however!