> obviously A computer at the location that is being used for some purpose

Well "A computer" could be any TCP/IP enabled device nowadays, including a router. So no, it's not reasonable to look at traffic coming from an IP, and say that traffic originated from the physical location of that IP, just because the LAN beyond that router is opaque.

I mean, several ISP IP addresses are involved with routing, but "everybody knows" they're shared machines. But again, simply because a trace route stops at a certain machine doesn't mean the routing actually terminates there - for most cases this is not true. It's just that the person behind the router with NAT often owns all devices on the LAN/opaque side. Using this correlation alone is dangerously inaccurate.