I may be wrong but I don't think they sweeten the tea then take the sweetening agent back out so it really isn't 'unsweetened' is it? Shouldn't it be sold as 'sweetened' on 'non-sweetened' tea? Just wondering...
http://www.thefreedictionary.com/unsweetenedAdj. 1. unsweetened - not made sweet
nonsweet, sugarless - not containing sugar
Non-sweetened and unsweetened mean the Same thing. It doesnt mean DE-Sweetened, THAT is what adding Sweetener, and taking it out would be.
Its like the word Unnecessary, or NOT necessary.
In the South (where I grew up, never got into tea), MOST people drink their tea sweet. They dont ask for a sweet tea usually, just a tea (or "ice tea"). If they want it non-sweetened they use the correct term, unsweetened, to ask for it.