Instead of using a stationary relay machine in Las Vegas, he should have used a laptop connected to a mobile broadband card. That would have been quite difficult to trace. Even if you can get the IP address of one of those cards, you still only have a vague idea of where it is. If you are the law, then how do you approach the judge to get a search warrant? You have no address to ask for a search of! You can buy such a mobile card in one part of the country, then carry it with you to another, so no useful address need be attached to it.
What's more, you can arrange to have such a machine mailed to a different location across the country. In one day, for the price of a Fedex, your relay is in a different state.
"On board, I staked out the bus’s backseat, where I could use my laptop without anyone looking over my shoulder. With a $150 wireless broadband card from Virgin Mobile, the only nationwide service that didn’t require a credit check, I had almost uninterrupted online access."
What's more, you can arrange to have such a machine mailed to a different location across the country. In one day, for the price of a Fedex, your relay is in a different state.