Here is the text of the US Code that prohibits labeling the bags:

"No common or contract carrier shall require or cause any label, tag, or other written notice to be placed on the outside of any package, luggage, or other container that such package, luggage, or other container contains a firearm."


A quick search shows guns stolen from luggage:


On Alaska Airlines:

http://www.fcw.com/blogs/archives/ed...m_readers.html


On United airlines.... mentioned that they maked the baggage tag with FFFFFF on it..... so everyone knew what to open and steal:


http://www.joehuffman.org/firearms/g...nesstories.htm