The Supreme Court's entire framework for Second Amendment cases is coming apart - Ian Millhiser @ Vox

[Igel]

1. Strikes me as not a hard rectangle to square.

To obtain explicit permission is a burden on the exercise of the right--the owner may not be there that moment, might be busy; might have a manager running the establishment. But property owners have full rights to simply post a notice saying firearms aren't allowed. If by the cash register, fine--see the notice, put down your intended purchase, and exit. Don't make it a postage-stamp sized notice, just reasonable.

Strikes me that's likely how "analogous" laws would have worked, historically. Maybe word of mouth would have sufficed, but gone are those days. If it works as a ban, it works as a ban. But it doesn't make a criminal out of somebody who walks onto private property that's not posted.