When the national anthem plays before the start of a U.S. sporting event, fans and players are expected to salute the flag by placing a hand over their hearts, often singing along. While not doing so is considered unpatriotic by some, athletes have at times abstained as a form of protest.
At the 1968 Olympics in Mexico City, U.S. athletes Tommie Smith and John Carlos each wore a black glove and raised a fist in the air during the medal ceremony as a sign of solidarity with those fighting for greater equality, which some dubbed as radical and an endorsement of the black power movement.