Before you blast someone, please have the intelligence to know what you are talking about. Mormons are permitted caffeine, they drink Coke and soda like anyone else. They are told to abstain from Coffee and certain tea products.
Most will abstain from alcoholic drinks, which is entirely up to them. However, unlike Baptists - Mormons hold the term "free agency" to be a basic tennant. Just because they chose not to partake, does not mean they forbid you from chosing. You are free to buy beer/wine/coffee and tobacco; it's YOUR choice, not theirs.
In any case, I did not say caffeine was prohibited. I said Mormons are "not supposed" to drink caffeine. In the English language most people recognize that there is a difference between the words "should" and "must".
As it is laid out in the handbook on their website:
"Members should not use any substance that contains illegal drugs. Nor should members use harmful or habit-forming substances except under the care of a competent physician."
Source: http://www.lds.org/handbook/handbook-2-administering-the-church/selected-church-policies?lang=eng#21.3
Caffeine, though not addictive, is habit-forming.