I think it should only be a prosecutable crime if you hack into a password protected account or if you tresspass to get the signal, such as the case of the SUV sitting in front of someone's house. If someone next door or down the road from a location you are
authorized to be finds out that you have connected to their (problem) unsecured network I don't think they should be able to file charges against you unless you actually cost them money, then it should only be a civil case, not criminal (with of course the exception if you were using their access to commit criminal activity

).