When I was a little girl (about 6), there were a rash of burglaries in my neighborhood. As my parents sat discussing this, I came up with a plan. We could put a sign in our yard saying, "Please do not steal." Then the person would know that you shouldn't steal. My parents didn't follow my advice.
The other day my husband and I were watching short clip on YouTube and came upon this Gun Free Zone bit from Fox. It is about two years old, so you might have already seen it. But I thought it was funny.