In the Flint, Michigan area you can't carry money. People shoot you for $3 bucks cash! Seriously, last year one guy bought $3 dollars worth of gas at a pump and went up to give the money to a person behind a plastic shield.
Soon as he put the $3 in the tray another man ran up and grabbed it. When the first guy yelled at him the second man shot him in the face and ran off with the three dollars.
I pay all my bills by internet and use plastic when I go out.
Edit: Also last year in Flint at 3:00 pm two teenagers rode their bikes up to a local bar, went inside and snatched a $20 bill off of a customer's table right in front of 4 people sitting there. A man and woman jumped up and the kid shot both of them. Then they rode off on their bicycles. They were caught later, but one of the people shot died. The shooter will be out in 6 years with good behavior.