Assault Rifle Seller Engraves "You Lie" On Automatic Weapons

So much for civil discourse, at least in South Carolina.  There a gun manufacturer is making commemorative assault rifle components with the words, "you lie" etched in the lower receivers.  The limited edition assault rifles are commemorating Republican Representative Joe Wilson's infamous heckle of President Obama during an address to Congress.

The gun manufacturer issued the following "promotional" statement:

"Palmetto State Armory would like to honor our esteemed congressman Joe Wilson with the release of our new 'You Lie' AR-15 lower receiver.... Only 999 of these will be produced, get yours before they are gone!"

I would expect if the inscription had been in Arabic with something like "Allah is Great" the manufacturer and all employees would be in Guantanamo already.  Why are these kind of not-so-veiled threats legal?  Where is the Secret Service on this?

Note: The statement which appeared on the company's web site is now mysteriously missing.  I wonder if someone from Washington might have had a word with them about their crazy idea?