He's using a single shared router for multiple PCs in a small office.
If it's like the cablemodem/router setup my roommate and I share, to the outside world, we show up as a single IP (the cablemodems IP) rather than as 2 separate IPs (one for each PC).
So the 4 accounts are showing up in the IP list at VGHD as a single "source" and not being counted.