Let’s start with one of my favorite words… because it’s been so applicable to so many people in recent years.

troglodyte (trog·lo·dyte): / TROG luh dite /
noun

(1) a cave dweller, especially prehistoric
(2) a person of primitive, brutish, depraved, or brutal character; a savage barbarian
(3) a person living in seclusion, especially antisocial
(4) a person out of touch with world affairs
(5) an animal living underground

[Via Latin troglodyta, from Greek troglodutai meaning “one who enters a hole” or “one who creeps into holes”; ultimately a derivative of Trogodutai, the name of an Ethiopian people.]

Usage: While isolated pockets of troglodytes still exist in Tunisia and China, it is often easier to view them in the modern world by monitoring the activities of George W. Bush and Usama bin Laden.