Please don't invoke the tired and ridiculous "URL:physical address" metaphor. A moment's thought is all that's required to see how dumb it is, every single time it comes up. In real life, one host sending another host a packet is nothing like physically breaking into a house. Houses have many purposes other than the distribution of leaflets. In fact, those physical entities actually designed to distribute leaflets are much more like internet hosts than houses are. No one ever got thrown in FPMITAP for taking one of each of the hundreds of different tourist brochures at a highway rest stop.