"Open to the public" considerations in trespass is generally a concept applying to commercial property. If you allow passage for all, you can't restrict it arbitrarily. No kids, no black people...you can't charge people with trespass if the property is generally open to the public (speaking of a mall rather than a bar with legal restrictions). My apartment building is not open to the public, though I suppose the sticking point is that my porch is, absent signage or other fence-y stuff.