6. The FARC
One of the most terrifying terrorist groups, it has toppled the Colombian government. Though the group is very hostile, it has also been a victim of brutal killings by the Colombian government.
In 2001, they rounded up a pro-FARC village and, over the course of three days, murdered between 40 and 80 of the inhabitants.
Others were beaten with rocks. One 17-year-old girl had her arms cut off with a chainsaw and was left to die in a ditch.
In 1997, 49 FARC sympathizers were hacked to death and dismembered in the village of Mapiripán, the remains of their bodies thrown in a river.