More than half a million “stop and frisks” by police each year have led to 46,000 annual marijuana arrests in New York City — mostly among blacks and Latinos — writes Drug Policy Alliance director Ethan Nadelmann in a July 19 column. Nadelmann notes that police data show that 90 percent of those stopped and searched on city streets — ostensibly for weapons — are non-white, and 85 percent are not charged with a crime. However, police still have collected personal information from everyone who is stopped — a practice that is slated to be curtailed under a new state law.