Clothing Supporting Military is Considered Violent

I have a son serving our country in Afghanistan. My youngest son wore a shirt to school with his brother's MP Company logo and was told to change because it demonstrated violence:

The logo:

OEF 2010 - 2011

School Policy:
Clothing with reference to obscenities or sex, violence, alcohol or other drugs, drug paraphernalia, tobacco or tobacco products, gangs or gang symbols or other inappropriate symbols are prohibited.

I'd like to apologize to my son's school and the school district for not only having a son in the military to protect your rights and freedom but also for having another son support his brother and the Army.

Oh, and in case you don't know what OEF stands for:
Operation Enduring Freedom

Ironic, isn't it?