30 years ago, an innovative approach dramatically lowered drug trafficking in Charleston, SC.  Police snapped pictures of people who come to buy drugs, thus cutting off sales. The cops gave copies of those prints to suspected drug dealers.  The dealers tossed them away.  Police issued them tickets for littering.  The suspected dealers threw  them away too.  When they didn’t pay, police arrested them on Friday nights (peak drug buying time) and held them until Monday morning court.