Many years ago (I don't know if the rule is still in effect) Houston's regulation about dangerous animals included lions and tigers and bears (OH my!) but also included snakes over 6 feet. This meant that if your boa constrictor got to be six feet long, it was no longer legal to keep. Forget keeping a Burmese Python (or even a Taiwan Beauty Snake!).
That is my concern whenever I hear of "dangerous" animal laws.