Why Hunger Games salute is Asia's latest protest symbol

As thousands of protesters in Myanmar continue to demonstrate against the military coup, one hand gesture has emerged as the movement's defining symbol - the three finger salute.

Originally seen in the Hollywood film series and books The Hunger Games, the salute has been adopted widely in Thailand as well in activists' protests against their military government.

But what does the gesture really mean, and what does its journey from the big screen to real life tell us about the power of protest symbols?