There are many laws regarding pet ownership and for good reason, if not involving an invasive species there's also animal cruelty issues. Pandas and other exotic animals need specialized care which a typical vet will not be able to provide. And that's if they aren't dangerous. Then there's the puppy mills, which is a huge issue on its own.
The puppy mills aren't running ads, they're using Groups and doing their advertising on the comments sections of local animal shelters. It's grotesque.
A post will be like "Meet Billy, he's been here at the shelter for 2 years," get a few sympathy comments and be followed up with a "look, we have puppies for sale!"
All existing pandas are owned by the PRC so the chance of somebody selling a panda for real, vs selling some sort of panda themed toy/book/etc, is virtually nil. No human would make this mistake; their filter is braindead.
Pythons, on the other hand, are often (illegally) sold, and can be extremely difficult to eradicate as an invasive species. Florida's Everglades are in trouble because people buy Burmese pythons and release them when they grow too big to handle.
That's not to defend Facebook's approach to ad management whatsoever. I definitely agree that it is far too blunt a tool for the problem.
Pretending the problem doesn't exist, however, because one example is unlikely is just intellectually dishonest.
That is true that the python trade is somewhat problematic and is accordingly regulated, but there are also a lot of people who are legally selling pythons on facebook and evidently don't get banned for it. Search "facebook python breeder" and they're easy to find. My conclusion is that the filtering system is totally and inexplicably capricious. A braindead computer program making indefensible decisions that it probably can't even justify to facebook employees themselves, let alone to the people it's banning. Maybe mentioning pythons or pandas alone would be fine, but both together gets you classified as an exotic smuggler dealing in literal bears? Who knows. Probably not even facebook knows.
Also it can be difficult to reliably distinguish between an individual passing on a pet, a properly licensed breeder selling animals, and a bad actor doing the same (selling exotic animals, being an unlicensed breeder in jurisdictions where this is not permitted (generally or for particular animals), etc.). For this reason many advertising companies simply have a blanket ban on advertising any animal trading. Being more selective potentially leaves them open to legal issues if the selection process makes a bad decision and lets something illegal through, and that risk is not worth taking in order to allow (and therefore take a cut from) the more legitimate trade.
