Apple decided to buy on Amazon.com products signed as official Apple products to check the quality of things which are sold in one of the most popular online shops. As it turned out, theoretically original chargers were actually fake. As established for the distribution of these loaders answers Mobile Star. Apple has announced that they intend to bring the matter to court, and also Amazon issued a statement in which it condemns the action of the Mobile Star.
Interestingly, Apple believes that about 90% of chargers sold on Amazon is counterfeit. So let's be careful if you want buy something from an unknown source.