Such huuuuuuge nonsense.

Reason Magazine - Hit & Run > New York City's 'Marijuana Arrest Crusade':

"Marijuana arrests have been rising nationwide since the early 1990s, but the increase in New York City has been much more dramatic. Levine and Small say the surge in arrests is largely a byproduct of an aggressive 'stop and frisk' program in which police pat down young men they (supposedly) suspect of criminal activity, ostensibly to make sure they're not carrying weapons. The targets of these pat-downs are disproportionately black and Hispanic, and so are the people arrested for marijuana possession. Between 1997 and 2006, blacks, who represent 26 percent of New York's population, accounted for 52 percent of the marijuana arrests; Hispanics, about the same share of the population, accounted for 31 percent of the arrests; and non-Hispanic whites, about 35 percent of the population, accounted for just 15 percent of the arrests. Yet survey data indicate that, if anything, whites smoke pot at higher rates than blacks and Hispanics."