"Forces of opposition bow down. You are single-handedly outnumbered."

That's how one advertisement reads for a semi-automatic rifle made by Bushmaster, whose AR-15 is increasingly the gun of choice for America's mass shooters, including the suspect in Sunday's massacre at a gay dance club in Orlando, Florida.

"Consider your man card reissued," another one reads, the text adjacent to a black AR-15 against a stark white background. The bright red logo of the gun's maker stands out: a red cobra coiled around a rifle, bearing its fangs.