Don Winslow said this quote

“ the Times says there's a heroin epidemic, Malone thinks, which is only an epidemic of course because now white people are dying. Whites started to get opium-based pills from their physicians: oxycodone, vicodin... But, it was expensive and doctors were reluctant to prescribe too much for exactly the fear of addiction. So the white folks went to the open market and the pills became a street drug. It was all very nice and civilized until the Sinoloa cartel down in Mexico made a corporate decision that it could undersell the big American pharmaceutical companies by raising production of its heroin thereby reducing price. As an incentive, they also increased its potency. The addicted white Americans found that Mexican ... heroin was cheaper and stronger than the pills, and started shooting it into their veins and overdosing. Malone literally saw it happening. He and his team busted more bridge-and-tunnel junkies, suburban housewives and upper Eastside madonnas than they could count.... ”