A U.S. Postal Service employee and another man were indicted in a scheme to steal more than half-million dollars worth of stamps and sell them online, the Maryland U.S. Attorney’s Office announced.

Prosecutors said Marvin Foster, a 54-year-old window clerk at the Elkridge post office, and Kyle Mathias, 23, could spend up to five years in prison if convicted.

The indictment alleges that from June 2008 through March 2009, Foster walked out of work with “bricks” of 2,000 stamps valued at $840 each and “coils” of stamps valued at $42 each. Foster allegedly gave the stamps to Mathias through an account Mathias set up on eBay.