The U.S. Postal Service released 20 Harry Potter-themed postage stamps today, but the move sparked controversy — mostly because the boy wizard isn't American.

The cash-strapped agency hopes the stamps, which feature images from the Warner Bros. movies, will get more people to buy stamps.

Volume of mail has gone down by 25 percent in the past five years, and the USPS is expected to lose $6 billion in 2013.

But while the stamps have been met with praise from Potter fans, not all muggles are thrilled to see Harry and his friends and foes on U.S. stamps.

"Harry Potter is not American. It’s foreign, and it’s so blatantly commercial it’s off the charts," John Hotchner, former president of the American Philatelic Society, told The Washington Post. "The Postal Service knows what will sell, but that's not what stamps ought to be about. Things that don’t sell so well are part of the American story."

The post office typically takes the advice of the Citizens' Stamp Advisory Committee when selecting images for new stamps, but the agency bypassed the panel on the Harry Potter stamps for one of the first times in the group’s 56-year history.

The Washington Post reports that members are "rankled."

The dispute comes after much friction between the Post Office and the committee, whose mission is to ensure that stamps "have stood the test of time, are consistent with public opinion and have broad national interest."

Postmaster General Patrick R. Don­ahoe said that the agency "needs to change its focus toward stamps that are more commercial" as a way to increase revenue.

Still, critics argue that Harry Potter stamps are a risky move after the USPS lost $1.2 million when it sold just 318 million of the 1 billion "Simpsons" stamps it printed in 2009 in honor of the TV show's 20th anniversary.

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