I wonder what the laws and regs are in other countries regarding the rights of ownership of your own reptiles?
In the US you can purchase most reptiles anywhere, from anyone, without any sort of permit. You can breed them, sell them, trade them, or just keep them without any strict or enforced regulations. Laws vary from state to state, but many states do require permits for keeping venomous (dangerous) and some native species.
Cross breeding is not illegal here, and yes, it does happen. Does it occur here more than it does in other parts of the world? Maybe.. but not as much as it seems.
Morelia are one thing. Jungle x diamond, jungle x coastal, etc, are indeed common. And while they are common (and all
Morelia), I know plenty of people who don't encourage such breedings. Chondro locality crosses are also common.. but they're the same animal. Boa and ball python morphs are big here, but those are also not crosses. And boa locality/sub species crosses? They don't bring in much money. People want pure locales these days. Locale "mutts" are often difficult to sell. From what I see (and I'm very active in the reptile market), the most popular reptiles here are bred to be what they are.
When strange or new crosses (meaning one species of animal to another, like ball pythons x blood pythons, or chondros x carpets, or Burmese pythons x reticulated pythons) do pop up, there is as much debate and argument about these animals here as there is there. Such creations are frowned upon by a very large number of reptile enthusiasts in the states, myself included.