Sparks - No: But Red Bull/Vodka - yes

So in the infinite wisdom of the FDA, prepackaged Energy/Alcoholic drinks are too dangerous to sell:

But bars are still able to sell Vodka/Red Bull, Irish Coffee, even Rum and Coke. While I will grant that the interactions between alcohol and caffeine are not well understood, but people have been mixing these substances for years without FDA involvement.

I scratch my head...