Hi. We just returned from 3 weeks in Vietnam. We spent the last week in Phu Quoc and were anxious to visit the fish sauce factory to learn about this famous fish sauce they make. We went and purchased 2 small bottles to take home. When they scanned my luggage they recognized the shape of the bottles (I presume since my pack zippers were zip tied shut and not opened) and paged me to come to the baggage area. They asked if I had fish sauce in my bag and I said yes. The guy then told me it's not allowed to take any fish sauce off of the island. I was surprised to say the least. Has anyone heard of this? What is the reason? They rave about this sauce and encourage tourists to visit the factory and buy some, yet it's not allowed to take any home. Would love to know more about this, and let others know as well.