The latest data on stop and frisks in New York City is nothing short of horrifying. Kristen Gwynne at AlterNet reports.

For the NYPD’s stats to add up, they’d have to have stopped every young, black man living in the city once–and then some. Both marijuana arrests and street stops are soaring under Bloomberg’s administration, but the data shows that rise in aggressive policing is only apparent in certain communities. Demonstrators stressed that pot arrests and stop-and-frisk have come to epitomize a city-wide problem requiring urgent redress.

In 2011 alone, more than 50,000 New Yorkers — 87 percent of whom are black or Latino — were arrested for petty marijuana possession. Though often considered a trivial arrest, a pot conviction can have serious consequences.

No kidding. But Mayor Bloomberg defends the policy, and its horrible consequences, by claiming it’s all about getting guns off the street:

The number of guns that we’ve been finding has continued to go down, which says the program at this scale is doing a great job….The whole idea here, John, is not to catch people with guns; it’s to prevent people from carrying guns. It’s like a stop we have for driving while intoxicated. It would be great if everybody said, “Oh my goodness, I might get stopped so I’m not gonna drink and drive.” That’s great. That’s what we want. That would be wonderful. And the fact that we’re getting fewer guns says the program is working. And the program will really have succeeded when we don’t get any guns.

Yet, as Jacob Sullum points out, searching people without evidence for the sole purpose of deterring crime is completely and utterly unconstitutional. Think about the actual words Bloomberg uses here: “The whole idea here…is not to catch people with guns; it’s to prevent people from carrying guns.” If you’re not actually even trying to catch people with guns, what on earth is the legal justification for stopping these guys in the first place? It’s illegal to stop someone on suspicion of carrying a firearm unless you have a reason to believe that they’re carrying a firearm, and just to clear up any confusion, being black doesn’t count as evidence that somebody’s got a gun.

Moreover, if this is really all about protecting the public from gun violence, I’d like to know why it’s necessary to arrest people who were unarmed but happened to have a little bit of marijuana in their pocket when police stopped them to look for guns. Concealed possession of small amounts of marijuana isn’t supposed to be a crime in New York anyway, but particularly in the context of a public safety policy solely aimed at taking weapons off the streets, why are marijuana users being arrested at all? It looks horrible in the press and badly exacerbates the appearance (heck, let’s just call it the reality) of racial bias underlying this whole hideous process.

The bottom line is that if this program isn’t all about stopping, searching, and arresting young black men for marijuana on a massive scale, then the procedures should be changed to produce some outcome other than a bunch of blatantly racist drug arrests. If anyone in NYPD needs advice on how not to racially profile people and arrest them for petty offenses, I have a few ideas, most of which revolve around the following theme: stop doing it.