They have some pretty strange policies here. I lived in Dalat, Vietnam for two years and went to an "illegal" Vietnamese language class. A teacher needs to have a license from Hanoi to teach Vietnamese to foreigners. And since it's apparently impossible to get a license, we were studying Vietnamese illegally. Eventually, the local police got wind of it and broke the class up. So all of the foreigners living here are essentially forbidden from learning how to communicate with the locals effectively. It's very bizarre.