Since the vast majority of "Arab Muslim's" are Caucasian, there is nothing "racist" about this ad at all. You really need to learn what RACISM is; it is NOT having a bias against a particular religious group.
Under the Constitution of the United States of America, unless you have been convicted of a felony; or have been adjudged to be mentally deficient either mentally retarded or mentally ill), you have an absolute right to purchase and own a firearm.
There are approximately 100 million "guns" of various types scattered all over the 50 States. Considering the vast numbers, and that the vast majority of gun related crimes are committed by people that do NOT have the legal right to have possession of a weapon, the rate of crime with legaly held firearms is actually very, very low.
I realize to that many Canadians, the absolute right to anything is scary, but you actually are very safe in visiting the USA. We will not shoot you, just for the sake of shooting you.