Why did Gregory Johnson burn the flag?
Similarly one may ask, when did Johnson burn the flag?
June 21, 1989
Keeping this in view, why is it OK to burn the American flag?
The Flag Desecration Amendment (often referred to as the Flag-burning Amendment) is an American proposed law, in the form of constitutional amendment to the Bill of Rights, that would allow the U.S. Congress to prohibit by statute and provide punishment for the physical "desecration" of the flag of the United States.
In Texas v. Johnson, 491 U.S. 397 (1989), the Supreme Court struck down on First Amendment grounds a Texas flag desecration law. The 5-4 decision has served as the center point of a continuing debate regarding the value of free speech as exercised through the burning of the U.S. flag as a form of political protest.