Zetas break out of prison in Mexico. Who are they?

The Mexican government deployed the military to states where the Zetas are active, particularly Veracruz, where violence flared in 2011. But despite the government offensive, which saw the takedown of 17 group leaders as well as their communications network in multiple states, the Zetas did not lose any territorial ground in 2011.  Instead, they expanded into new states. One reason for their fortitude is their ability to recruit recent army deserters and police officers. Stratfor forecasts that the Zetas and the Sinaloa Federation will remain the two dominant groups this year, and an end to violence might only come with the brokering of an unlikely truce between the two.