McCann Erickson's Bucharest office has won the first two Grand Prix of the 2011 Cannes Lions Festival of Creativity—in the Promo & Activation and Direct contests—for a sneaky campaign in which it replaced the familiar Romanian flag on the local ROM candy bar with an American flag, sending a country into panic.

     The hoax was widespread and elaborate. The packaging was changed first, reinforced by promo activity and advertising that pointed to a microsite and the brand's Facebook page. Angry Romanians began stockpiling the old ROM bars with the Romanian flag. The second phase of the campaign revealed the deception and celebrated Romanians' newly discovered patriotism.

     Anti-American sentiment—often a big winner in France.