The important general policy discussion on this topic occurred long ago and ATC wrote a position paper to guide those who insist upon providing so-called trail magic. Unfortunately, the redesign of their website has resulted in much useful information becoming unavailable.
I would think common sense would lead one to inquire with local trail maintaining clubs about their related policies. The more local clubs do to clarify their expectations and the more consistent they are in implimenting them, the fewer misunderstandings are apt to result.
Even people who may claim to be affiliated with PATC surely realize they can't have it both ways, not even when trolling online.