I think a guy trying to build a nuke in his basement or messing with dangerous chemicals is plausible enough. Juggling cyanide-filled glass balls is absurd, but so what? I can think of an example from real life if you prefer: the neighbors start a giant bonfire and leave it burning overnight with no one attending it. This happened in my neighborhood a few years ago. In fact the fire was still burning underground for several weeks, near a ton of brush and forest, in midsummer. No NAP violations as a result of the fire, but actions violating the owner’s property may well be taken (and justified as legal) such as entering the property and dousing the fire with water even in anarchy or under a system with PDAs and private courts.
Reading into my post a fair bit aren’t you? [;)] I don’t support minarchy. I support anarchy. I’m just making the point that if you want private courts to decide the law with no monopoly power keeping them in line with a certain set of rules (for example the NAP), they can be expected to adhere to that set of rules only to the extent that there is strong consumer demand to do so. In other words, if we want private courts to make the laws, we don’t get to decide what laws they make, beyond our own tiny individual influence as a consumer of law on the market (and of course our ability to gradually influence and educate other consumers on such a market).