I'm surprised all of these ppl stayed in the US. I would imagine it's a lot harder to track someone down if they disappeared to the other side of the world.
Pick the right country and that's not a problem at all; a couple of strategic bribes can get you out of trouble in most of the world.
If the problem is money however, then that's a valid issue. Because all of the above cost significant amounts of money.
Also, U.S. Mexico border is not that hard. Tons of people and drugs do it daily.