That was exactly my point. The journalist's statement ("Pimps often move their human cargo across the country, making it difficult for girls to contact their families.") made absolutely no sense.
If a kidnapper has somebody locked up, it really doesn't matter if they're ten miles away or a thousand. Taking a victim across the country has almost zero effect on their ability to contact their family.
It definitely paints a picture of children being picked up in one place, and used in another. Maybe the aspect of being 1,000+ miles from home, helps to discourage the kids and convince them that it's hopeless, they don't know anybody nearby, there's nobody's house they can run to, they'll never get back home.
It hardly makes sense to object that "That's unreasonable" (or "illogical"), since kids --- but especially kids who have been raped, beaten, terroristically threatened, drugged, etc. --- are not known for their cooly logical thought processes.