The “don’t tread on me” flag is a symbol used by the tea party movement. I will bet you dollars to donuts that is the reason for banning it. Has the LGBT rainbow flag been banned too?
Better to take it off, and not identify yourself for special treatment when Obama’s Special Order 66 comes.
SeALs are Navy, but the Army was always funny about symbols. The 45th Infantry Division had to change their insignia. In the 1930s it was a yellow swastika on a red background.
http://en.wikipedia.org/wiki/45th_Infantry_Division_(United_States)
http://en.wikipedia.org/wiki/File:45th_Infantry_insignia_(swastika).svg
While it is probably true that the slogan is the target, the ‘Don’t Tread on Me flag in question is not the one used by the Tea Party.
The Tea Party has adopted the Gadsden Flag as one of their symbols.
The flag the SEALs have/had on their uniforms is the First Navy Jack.