Beyoncé’s black power salute that kicked off her appearance during Sunday's Super Bowl halftime show resulted in criticism from former New York Mayor Rudy Giuliani. The salute was a reference to Tommie Smith and John Carlos, two American athletes that famously gave the gesture while receiving medals at the 1968 Olympics:

Beyoncé's backup dancers also posed for a backstage photo paying tribute to the Black Panther salute:

Sources: Business Insider