Recently Activision announced a Destiny promotion with Red-Bull. If you buy a specially marked can of Red Bull, you can unlock an XP boost and an exclusive quest in the upcoming Taken King expansion.
The cans went on sale July 1st, but if you go buy out and buy one you have a chance of getting a code that has already been used. It seems that the codes on the cans are pretty easy to figure out and a great number of people have unlocked the XP and quest just by making a few guesses. The promo site has been very slow and at times it has been inaccessible, this is more than likely people trying to guess the code without buying a drink.
One player has already reported that their purchased drink has a code that was invalid.
Neither Bungie, Activision, or Red Bull has commented on this matter and since getting a code without buying a can of Red Bull is considered theft there’s not telling what form of action they might take.