I'm one of the people whose home LAN is completely exposed to TPL. There's an amount of "screwing around" where I wouldn't care. If you want to print an xkcd cartoon to my desk, fine, lol, a minor surprise in my day. If you print 1000 pages of dicks while I'm not home so that my paper and toner run out, that would be uncool. After years of caring about this problem, I came to believe that this kind of normative social contract cannot scale to include "everyone in the entire world," and that this kind of unwritten normative code is the only thing that makes any social space tolerable.