If you're not looking for illegal drugs, you will not find them.
If you're not looking for illegal guns, you will not find them.
And basically anything illegal. If you don't want to get a fake passport to migrate, forged documents or money, slave labor, hitmen, rare and endangered animals to hunt or keep as pets... you won't find them.
If you want to, you will. Certainly if you have the money or power to pay for the added difficulties of their illegal aspect.
Same with kiddie pros.