New Posted Sign

When entering Riverbend, visitors are greeted by a new posted sign. This one is near the Private Property sign that has been up for a couple of years. Similar signs are now posted throughout RB.

The surprise is that our property is now posted by a group called the "Poor Boys HC."  I assume that I can still enter my property, but do I now have to carry proof of ownership? Other visitors to the property who are not owners have to be prepared to show written permission to be there. If I am approached by someone claiming to be part of the HC do I have to leave? Who authorized these postings?