They were asking personal information not relevant to the purposes of any of the agencies at the airport; questions that federal employees are usually specifically trained NOT to ask because they are illegal. There is no identifiable connection between the questions asked and any potential agency. Because complaints must go to the proper agency and I only transited through MIA I was hoping that someone would have gone through international baggage pick up/customs and flight connections area and may know whether those stationed at the perimeters are border patrol, TSA, police, security, or some other agency I am unaware of. There are only two exits (connections and destination) and I took the connections exit from customs area. Only one person was stationed at the corridor since it is narrow and I am guessing to prevent people wandering into the international customs area rather than interrogating people like me who were exiting.