A highly infectious disease that afflicts those who have the opportunity to shoot AR-15 patterned rifles. Early signs of infection include an ear-to-ear grin upon firing one of these rifles.
Please note that EBRD does not stop once a victim procures one evil black rifle. Often, the disease will drive the victim to procure multiple evil black rifles, in various configurations. Carriers of the disease can often be found at shooting ranges, shooting rounds and talking smack with fellow victims, or at gun shops, where the black rifles are liberally coated with oil to protect against customer drool.
Please note that the AR in AR15 stands for Armalite Rifle, not Assault Rifle, as gun control advocates would mislead you to believe (AR15 patterned rifles for sale in the US are NOT assault rifles as they are not capable of automatic fire).