Maybe there should be signs at the pet store and stores that carry bait and fishing gear also that clearly state it is illegal to release non-native and fish that have been kept in aquariums.
The sad part of any responsibility, like parenthood or pet ownership, is its availability to the lowest common denominator. Gotta retard-proof everything.
It is easy to get rid of an unwanted fish. Look for a small mom and pop fish store. Give them the fish. I have never been refused and got rid of a ton of baby platties that way.