not looking for a fight at all....
I was just under the impression that most fish that are problematic to an environment are simply not sold in those states (snakeheads, piranha, etc)
the majority of aquarium fish would simply be eaten by larger fish in public waters...or not survive the condtions/change in ph/temperature, etc....
I dont believe in a "commitment" as I'm a fisherman, and go through 3 dozen LIVE fish a weekend as bait, not to mention the dozens of goldfish/guppies I buy as feeders for my meat eating fish...so the loss of one mollie or pleco to a bass isn't going to make me a bad person IMHO
Also, note this thread deals with a pleco...the most problematic fish sold in stores are plecos, which grow rediculously fast and are typically tossed into 10 gallon tanks.
If the post was dealing with a snake head, alligator gar, piranha, or something that would tend to get a little larger while still being fairly hardy then I might have offered other advice....