From Nicki Minaj, to the young stars of Hugo, to Kim Kardashian, celebs have been flocking to Twitter to voice their urgent opposition to Joseph Kony, leader of the Lord's Resistance Army (more commonly known as the LRA), one of central Africa's most violent rebel groups. At the helm of the online campaign is Invisible Children, a charity group that aims to raise awareness about Kony's brutal human rights violations in Uganda.