This is one of those rare times I agree with facebook. Why is this Facebook's problem? Sounds like Brazil should be enforcing their laws better. Facebook hosts for-sale postings, how reasonable is it for them to vet every post against scams and illegality?
If you follow this line of thought, the conclusion seems to be that if Facebook were to run ads for illegal drugs, explosives, or humans, it would simply be an indication that some country should be enforcing it's laws better. And Facebook would be totally in clear to continue showing those ads. This seems obviously wrong.
Using the same logic of enforcing marketplace, there needs to be an observer for every private conversation on messenger so that no illegal pictures are sent.