Stands for Centro para la accion legal en Derechos Humanos. (The center for human rights legal action)
A kick-ass human rights group in Guatemala, CalDH is fighting the legal battles of the downtrodden of Guatemala. At tremendous personal risk (many staff members have received death threats), they fight to get court orders to exhume mass graves and attempt to prosecute military officers for war crimes committed during the Guatemalan civil war. They make every attempt to raise awareness of 'social cleansing' and to prosecute the murderers of the prostitutes, transvestites and street children who are routinely murdered (usually by the police, which is part of the reason these murders are never investigated). All in all they try to be a voice of legal integrity in a place where the legal system is owned by criminals.
Not only that, they are a bunch of the best people anywhere and they throw fantastic parties.