First off, few people actually use postage stamps any more. Email, social media, and cell phones are killing the post office. The USPS is searching for ways to stay afloat, and their knees weaken at any claim of politically incorrectness from politicians.
Their mistake here was thinking Michelle Obama might help them roll out a line a cute stamps that promoted exercise. See Dailycaller.com.
Officials raised objections to a stamp depicting a man doing a cannonball into a pool, a stamp showing a child doing a handstand without a helmet and a stamp with skateboarder no wearing kneepads.
Come to think about it, the proper nanny could find some danger in all of those activities.
Perhaps they should lower the bar and focus on getting the kids to sit up straight while they play video games.