The August 2013 issue of Harper's includes a transcript of a speech given by Mark Kingwell in which he states:

You can either use a pillow or a gun to kill a person, but people with guns kill more people than do people with pillows.  Marshall McLuhan was correct:  the medium really is the message.

 What is the message?  It is not complicated.  If you own a handgun or, certainly a semi-automatic rifle, the message you are sending is that you are willing to kill another human being at your own discretion.  That is the only reason to own such a weapon.  One can make the case that the message is that the gun owner will protect him/herself at any cost, but the end result is the same.  Gun owners tell us:  I will kill you if I feel personally justified in doing so.

The amazing thing is that millions of Americans send that message every day.