A common insult used against fans of the
Portuguese Football Team SL Benfica. It also has to do with Andrades, a "Cangaceiro" from Northern Portugal and the word "Lampião" in truth means a post of light that emits a strong, red light, since Benfica's color is red.
Basically, when you call someone a Lampião, you're calling them a
disgusting, no good Benfica fan. Which you shouldn't. Respect all teams. (Coming from a Sporting CP fan.)