That is the fear even though I doubt they would do well in the states. Most of the country gets too cold and places like Florida probably aren't too hospitable to them either due to higher oxygen demands. As shallow as Okeechobee is I doubt the fish would do well there and I think it would struggle in
most rivers. This falls like many other fish to regulation. River Monsters is not helping the hobby. Lawmakers are seeing these exaggerated horror stories and then panicking when they see the fish is in the trade.
You can occasionally find them at the supermarket. So you can still enjoy the fish in another way. They are quite tasty.