The guns used in Paris attack were illegal attack weapons imported from former Yugoslavia after the war. When you have a war running next door for several years, this can kind of things are bound to happen. The AK47 is quite popular with drug dealers, but it is mostly used against "competitors". Most Europeans don't have guns and the gun market is very regulated. We don't feel the need to have a gun in case somebody breaks in the house because it is unlikely he would have a gun anyway.