Four-Armed Somali Pirates

A few days ago I heard on the radio that a US cargo ship was attacked by four-armed Somali pirates. This seemed like a most alarming prospect: They could hold and aim a rifle with two of their hands while wielding a sword in a third.

Statistically, you'd expect at least one of the four arms to have a hook instead of a hand, but that just tells you what an advantage this must be for them.