Art, I'm not bringing this up as "the law in such-and-such state," but rather as a point of interest. Historically (seventeenth century, if not earlier), trespass to land was known as "trespass quare clausum fregit," or "wherefore he broke the close," the "close" being the enclosed boundary of the land, with or without a fence. In most torts, the plaintiff has to prove damages, but that wasn't required for trespass qu. cl. fr.--the common philosophy was that merely treading on someone's grass constituted damage. This is the basis of modern trespass-to-land. Granted, different jurisdictions implement it differently, but the ancient doctrine is that you do damage merely by stepping foot on my land, and it's therefore actionable. Just a point to think about for those who claim a right to use another man's land, even if you claim not to hurt anything.