As the nation's biggest city deals with threats of terrorism and a variety of violent crimes, carrying a little bit of marijuana is still a big deal.

There are more arrests for low-level pot possession in New York City -- about 50,000 a year -- than any other crime, accounting for about one of every seven cases that turn up in criminal courts.

It's a phenomenon that has persisted despite more leniency toward marijuana use -- the state loosened its marijuana-possession laws more than 30 years.

Critics say the deluge has been driven in part by the New York Police Department's strategy of stopping people and frisking those whom police say meet crime suspects' descriptions. More than a half a million people, mostly black and Hispanic men, were stopped last year -- unfair targets, critics say. About 10 percent of stops result in arrests.

The department says that the strategy's main goal is to take guns off the street and prevent crime, and that the tactic is a life-saving tool. But critics say officers looking for guns in pockets more often find pot and -- though state law says the drug is supposed to be in open view to warrant an arrest -- lock up the possessor anyway.

In response, Police Commissioner Raymond Kelly recently reminded officers they can't make arrests for small amounts of pot in people's pockets or bags -- and can't trigger an arrest by searching people or telling them to empty their pockets.

"No one has showed me any evidence that this is how a large number of arrests are being made," he said. "But the allegation was made. So, in order to clear up any confusion that may exist, we put that order out to make certain that officers know that they cannot be the reason for someone displaying (marijuana) publicly."

Kelly said the vast majority of pot arrests come from undercover officers who witness hand-to-hand drug transactions or people smoking pot in public. And, the department says, as low-level arrests have risen, violent crime has decreased dramatically.

But many New Yorkers, mostly black and Hispanic men, say they're being targeted in the name of keeping the city safe.

Bronx community organizer Alfredo Carrasquillo, 27, estimated he's been arrested on marijuana possession charges more than 20 times, starting when he was 14 and police ordered him to empty out his pockets outside his high school. He says he was arrested, but was never was found smoking the drug or holding it out in the open -- though a 1977 state law says those with 25 grams of the drug or less in their pockets or bags should only be ticketed. Legally, it's a violation that doesn't result in a criminal record.

"We weren't stupid enough to smoke it in the middle of the day," he said.

Gabriel Sayegh, the New York director of the Drug Policy Alliance, a group critical of the national war on drugs, said the department benefits from the arrests.

"Every year, they're bringing 50,000 people into their system," he said. "A significant portion of whom have not been arrested before.

Even if the cases ultimately get dismissed, as most first-time marijuana-possession arrests do, police net names, fingerprints and other information for law-enforcement databases, he noted.

New York's lowest-level marijuana-possession charge -- criminal possession of marijuana in the 5th degree, a misdemeanor -- has been the most common arrest charge in the city for much of the past decade, and the numbers have been steadily rising. So far this year there have been 38,359 reported arrests. Last year, there were 50,377 arrests citywide, up from 46,492 in 2009, according to statistics from the state Division of Criminal Justice Services. That represents about 616 arrests per 100,000 city residents.

Police officials say the studies done by the New York-based Drug Policy alliance others are flawed, and also ignore the context of what has been happening in the city as these arrests continue to rise. Overall, they cite significant decreases in murder and major crimes -- the last decade has seen the four lowest annual murder totals since at least 1962.

"Drug use advocates ignored both the very high incidents of violent crime when low-level offenses were enforced far less vigorously than today, and the steep decrease in violence crime that occurred when less serious offenses, like marijuana, were consistently addressed," said Paul Browne, the department's chief spokesman.

Comparing different cities' arrest data is difficult because drug laws and data-keeping differ. In Chicago, possessing even 2.5 grams of marijuana is a crime that warrants arrest, and possessing up to an ounce is considered a misdemeanor. Chicago logged 22,291 arrests on that and other misdemeanor marijuana possession charges in 2009 and 22,764 last year, or about 826 arrests per 100,000 people, according to data from the Chicago Police Department provided to The Associated Press.

Earlier this week, a Chicago politician proposed to make possession of up to 10 grams of marijuana a summary offense, like a parking ticket, with a potential $200 fine, rather than a misdemeanor that carries possible jail time.

Chicago Police Superintendent Garry McCarthy didn't endorse the ordinance but has signaled he's open to it.

"With minor possession, it would be in everybody's interests to free up officers," said department spokeswoman Sarah Hamilton.

In California, possession of up to an ounce of marijuana was a misdemeanor until last Jan. 1; now it's a non-criminal infraction. The City of Los Angeles had 3,465 such arrests in 2010 and 4,714 in 2009 -- about 90 arrests per 100,000 residents, according to data from its police department.

In New York, two state lawmakers have proposed a similar measure: to make possession of less than 25 grams -- 7/8 of an ounce -- a violation, whether it's in the open or not.

It's difficult to put a price tag on the city's arrests. They add to already-busy arraignment court dockets; many cases are put on track to be dismissed quickly. Others take longer to resolve, sometimes because defendants have prior criminal records.

A report done earlier this year for the Drug Policy Alliance concluded it cost an estimated $75 million in 2010 to process, jail and prosecute the low-level arrests in New York. That figure was a compilation of estimated court costs, police manpower and jail time, averaging about $1,500 per arrest -- a cost shared by the state and city. The city budget alone is $65 billion.

The arrests can carry a heavy personal cost. An arrest alone can prompt a child-welfare inquiry, jeopardize job licenses and turn up in a background check.

Chino Hardin, 31, has been busted on marijuana charges more times than she can remember, most recently in 2003.

For each arrest, she pleaded guilty to misdemeanor possession and was released, sometimes with a community-service sentence, Hardin said.

"At the time, I didn't really have a good grasp of the laws around possession of marijuana," she said, and after hours in custody, "all I wanted to do was just get out and go home."

She now has a job at a juvenile-justice group that entails telling teens about their rights in a police stop.