On a warm spring day, strolling in south London, I heard demanding voices behind me. A police van disgorged a posse of six or more, who waved me aside.
They surrounded a young black man who, like me, was ambling along. They appropriated him; they rifled his pockets, looked in his shoes, inspected his teeth. Their thuggery affirmed, they let him go with the barked warning there would be a next time.