The U.S. Postal Service stirred up quite a controversy when, in 1996, it decided ot issue a Christmas stamp featuring a painting of the Madonna and Child, reproducing a 1712 painting by Italian artist Paolo de Matteis, which showed the baby Jesus's penis.
The controversy was described in detail in the authoritative Stamp Magazine, Linn's, in both their print and online versions. The story has since disappeared from the online report.
The original story was by columnist Peter Rexford, in the Washington Post. He reported that a postal employee, apparently embarrassed by an antomically explicit baby, airbrushed the figure into an asexual being. In time the postal authorities came to their senses and undid this assault on the original work of art.