Homeopathy is under fire because, in a modern world where evidence is easy to find, people can easily learn that duck liver diluted in trillions and trillions of gallons of water will not actually cure the flu.

Writing on LiveScience, Christopher Wanjek details the U.S. Supreme Court case against Zicam, a homeopathic produced removed from the market after the FDA saw enough cases to warn that the product could lead to a permanent loss of smell.  Unlike goofy duck liver or harmless water, which is unethical because it bilks unsuspecting people out of their money with spurious claims, Zicam does actually do something because it contains zinc.  Unfortunately the thing zinc does when sprayed in the nose is remove sense of smell.   It just doesn't cure a cold.

LiveScience for the full scoop.