With physical property, the onus is on the owner to both demarkate the protected area and mark it as "no trespassing". For example, I own a couple of vacant lots in town. Kids play there, college students cut across them as a shortcut to the local 7-11 etc. It's MY land, shouldn't I be able to sue every man-jack of 'em for using my resource without permission? The answer is "NO". They're not violating a physical structure (which is assumed to have an implicit no-trespassing sign). I would have to fence (or otherwise deliniate) the area and post "No Trespassing" signs prominently around the perimeter before I can prosecute. The open, unfenced, unposted land is considered an implicit invitation. So why, for real property, does the lack of a fence imply permission, while in the wacko-world of IP using an open router is a crime? The physical property laws, to me, are pretty logical. For the record, I'm happy to see kids playing on the lots, and a bit less happy to have to pick of the trash folks drop there. However, I have no intention of slapping "No Trespassing" signs up and start suing folks. Can't we all just get along???