2. Why have you heard of them before?
If a sensational attack in Mexico makes US news, chances are the Zetas are the suspects. One of the worst events in Mexican President Felipe Calderon’s five-year strategy against drug trafficking organizations was the arson attack at a casino in Monterrey in August of 2011. Some 52 people were trapped inside and killed, many of them middle aged women. The previous year, 72 migrants mostly from Central America were found killed en masse in the northern state of Tamaulipas, allegedly hauled off buses and killed after refusing to work for the Zetas. They are suspected in the shooting death of a US immigration agent in Mexico last year, and facilitating a prison riot that killed 44 people, mostly members of the rival Gulf Cartel in Nuevo Leon in February 2012. The prison riot was deemed Mexico's worst, and authorities believe it was a coverup for the escape of 30 Zetas. State Gov. Rodrigo Medina said the riot was premeditated, and investigations are underway into prison staff involvement in the murders and escape, reports the Wall Street Journal.