Then that law is the same as many other states (including my own). "No gun" signs on buildings don't carry the force of law. A person can still enter while OCing or CCing. If you are asked to leave by the owner, you have to comply or can be charged with trespass. Some states, like Ohio, the signs do carry the force of law. Not having those signs or laws doesn't seem to increase the rate of crime so... moot point.
Like I said though, that's why if people are against carrying guns, just post the sign and I won't frequent the establishment. Doesn't have to get stupid.