There are some really cool fish out there that just also happen to be illegal to keep. Not all are voracious killers, but all do cause havac when out of their native habitat. I would love to have a large snakehead or 3 in my outdoor tank,,, but the security of keeping them there is too difficult. Hawks/cranes/racoons/cats/dogs/floods have all distributed a variety of fauna that we thought were safe and sound. The fish farms here in Florida are responsible for so many unintensioned releases of non-native species because of flooding of outdoor ponds that have no means of secondary entrapment. Most times its just not posible, a pond dug into flat land and then flooded, hhmmm. Now if I had a basement tank with a radioactive bleach mote around it. Ah, who am I kidding Ive probably had more illegal fish over the years than most people on this board... BUT I did take precautions, kept them indoors and never had a release. Also almost all were caught in the wild locally.
Now what to do about the BOA CONSTRICTORS , their going after our precious alligators...