Throughout history, flags were a way of marking territory. Ships at sea raise a flag to denote which country they represent. The flag at Iwo Jima meant US Soldiers were claiming a win and authority over that land. When we planted the flag on the moon, we were claiming it for the US.
Therefore, when a person of any race/ethnicity/nationality raises a foreign flag on US soil, that person is claiming US land is the posession of the foreign country. Doing that either makes you a traitor or an invader. In a different place and time, that act would have gotten you shot.
It is also an insult to all Americans, especially those who gave their life to protect US soil represented by the US flag.





