There are two kinds of New Yorkers: those who lock their doors, and those who do not. The Times investigates some of those brave residents with open door policies, like 63-year-old real estate firm vice president Joyce Weisshappel, who never locks her door. In fact, Weisshappel doesn't even know where her keys are. Though Weisshappel lives in a luxury apartment building with 24-hour doormen, others, like 52-year-old Brooklyn resident Sarah, don't have that kind of security. Sarah leaves her door unlocked for brief trips out — like when she walks the dog — though she locks it when she leaves for extended periods. "It's a bit of a habit and maybe a bit of a dare, as I always considered myself lucky."

Unsurprisingly, some people who don't lock the door get burglarized, according to Inspector James Murtagh of the Upper East Side's 19th Precinct. "My crime prevention officer goes to visit each one of the burglary locations," he said. "And the resident will often tell the officer, 'I don't lock the door,' or they feel safe or it’s a safe neighborhood. They blatantly admit it to us. The logic to them is they feel comfortable enough to leave it open." Of the 19,263 burglaries that took place in the city in 2009, 5,041 didn't involve forced entry (though those figures also include burglaries of commercial properties and crimes involving open windows, illegal use of keys, and crimes committed by perps who were allowed in).

People who lock the door are "incredulous" that anyone wouldn't, the paper reports. "It's the height of naïveté," said a New York businesswoman, who identified herself as a Double Lock Person. "I live in a high rise with a doorman, I've been there 15 years and I've never heard of a burglary in the building, but that has absolutely nothing to do with it — it's common sense."