Oh, and watch the video, it's funny.

D.E.H.T.A. (Druids for the Ethical and Humane Treatment of Animals) is actually a reference to P.E.T.A. (People for the Ethical Treatment of Animals), an organization in the real world known for various acts of extremism to (in their view) defend animals from humans. Just as DEHTA is a violent response to poaching in Azeroth (which Azeroth's heroes do an awful lot of), PETA sometimes does some awful weird things to get attention here in the real world - for example, throwing red paint on coats made out of animal fur (which are usually worth a crapload of money).

DEHTA is a reference to PETA, People for the Ethical Treatment of Animals.

http://en.wikipedia.org/wiki/People_for_the_Ethical_Treatment_of_Animals
(warning: contains PETA ads with naked people)

DEHTA is either biting political commentary of PETA's rather large amount of crazy and tendency to associate with ALF terrorists, or an over-the-top strawman of their mission. Depends on whether you think they are crazy or not.

I personally enjoyed doing the DEHTA quests, because fighting the Nesingwary Lackeys was like being in an episode of Captain Planet.