The opposite of a "gun free zone" is a location that does not ban weapons. An attempt at yet another mass shooting this past Sunday at New Life Church in Colorado Springs, Colorado was stopped short by Jeanne Assam, a CCW licensed armed member of the congregation that was legally carrying a concealed weapon when she pulled out her gun & shot the deranged maniac who had one thing on his mind - killing as many innocent victims as possible. He was armed with 2 handguns, a rifle, over 1,000 rounds of ammunition, and was working his way towards a large congregation in the church when she brought his shooting rampage to an early end.
He had made one fatal mistake (besides the obvious mistake of going off the deep end with plans to murder as many people as he could) - he forgot to go to a gun free zone. Instead he went to a freedom of choice zone where citizens were free to choose for themselves to be armed or not to be armed. Lucky for the hundreds of potential victims in the building, it was not a gun free zone, and at least three members of the congregation had exercised their choice to be armed.
See further details & links from Say Uncle, Call me Ahab, Of Arms & the Law, Instapundit, Front Sight, Press, massbackwards, The War on Guns, Ted Nugent, John R. Lott, Xavier Thoughts, Good for the Country, Jerry Ahern, and Snowflakes.