Unbroadcasted/Unsecured wi fi,any help appreciated. Thank You.?

Is it possible to get a software which will find non-broadcast or unsecured wi fi networks. The reason why I am asking is because my understanding is that if you access an unsecured wi fi network whether it gets broadcasted or not it is legal and you're not breaking the law. Is this true? Or is there any other way of doing it? Please don't take this message as inapropriate as I am not trying to discusthing to do with breaking the law, that's why I am asking this question?Any help is much appreciated.Thank You.