premise: MS-13 is cruel for its tactics.
hypothesis: MS-13 . They are notorious for their use of violence and a subcultural moral code that predominantly consists of merciless revenge and cruel retributions . This cruelty of the distinguished members of the `` Maras '' or `` Mareros '' earned them a path to be recruited by the Sinaloa Cartel battling against Los Zetas in an ongoing drug war in Mexico .