there have also been several Nile Crocodiles found in the everglades. pretty sure those were always banned. The burmese python problem has gotten out of control here though. The even eat american alligators. We hunt them by the thousands every year, they just breed too fast to keep up with. Unlike most large constrictors, burmese pythons have a voracious apetite. they can eat almost daily whereas an anaconda eats every 6 months or so in the wild.
The problem with bans is they make the problem worse. The cost of the animals goes up and demand goes up. just makes them more appealing to breed and sell. Look at the piranha. since it has been banned in most states, many many illegal markets have surfaced for their purchase.
It is a major issue but ussually our attempts to curtail it make it worse. i sure hope the Nile croc population doesnt pick up down here. If they breed with the American crocodile we will have a super predator in our hands.