In spring 2012, a talented young New York City chef named Hwangbum Yang, 26, was headed uptown after a typically long shift at The Modern — a trendy restaurant tucked away in a Manhattan art museum. A Sunday school teacher and son of immigrant parents, Yang dreamed of one day returning to Korea after making a name for himself as a premier chef in the big city.

That night, however, his dream of making his parents proud was abruptly cut short. About two blocks away from his apartment in the Riverdale section of the Bronx, a twenty-something in a grey hoodie stopped in front of Yang and fired a single shot straight into his chest. According to an eyewitness, the thief then kicked over Yang's body, quickly rummaged through his pockets, and took his iPhone. A wallet full of cash was left behind.

Police later found the budding chef's phone on Craigslist. The asking price? $400.

Yang's story is sad and all too familiar. A cursory Google search for "iPhone robbery" or even "iPhone stabbing" reveals a laundry list of gadget-related violence and crime. While only a small percentage of muggings are fatal, Yang was just one of thousands of victims who have fallen prey to thieves in big cities around the country. In San Francisco, for instance, an astonishing half of all robberies now involve a cell phone. New York has seen a 40 percent spike in cell phone-related robberies since just last year, when more than 15,627 iPhones and iPads were reported stolen.

"With 1.6 million Americans falling victim to smartphone theft in 2012, this has become a national epidemic," said New York Attorney General Eric Schneiderman.

Apple's mobile products in particular can fetch hundreds of dollars on the secondary market, where demand is strong. According to Reason, "high tariffs in countries like Brazil can drive up the price of a new entry-level iPhone 4 to $1,000, so used ones go for as much as $400 there. Here in the U.S., secondhand dealers buying in bulk on Craigs­list pay as much as $500 for a used iPhone 5."

"If you took out thefts of Apple products," New York City Mayor Michael Bloomberg recently told the New York Post, "our total [major] crime rate would be lower than it was last year."

That's why on Monday, when a revolving cast of Apple executives took the stage at the Worldwide Developer Conference in San Francisco to reveal iOS 7, the system's single most important new feature wasn't a new-and-improved Siri or depth-inducing parallax scrolling — it was a simple Activation Lock that makes it exponentially more difficult for thieves to resell a stolen iPhone. From Apple:

Now turning off Find My iPhone or erasing your device requires your Apple ID and password. Find My iPhone can also continue to display a custom message, even after your device is erased. And your Apple ID and password are required before anyone can reactivate it. Which means your iPhone is still your iPhone. No matter where it is. [Apple]

iPhones, Androids, and Windows Phones already have the ability to remote-wipe a phone once it's stolen, or even use the camera and microphone to spy on whoever snatched it. (PC Mag has a thorough rundown of how to do that here.) Some smartphones even come with GPS trackers to help users locate precisely where their device is — although once you do find it, you're mostly on your own.

Apple's Activation Lock is different. Without a technical background, thieves can't simply wipe a stolen phone that has been locked to resell it on Craigslist or eBay. This kill switch effectively strips the iPhone of its currency on the secondary market, making the hijacked device nothing but a brick.

As far as I can tell, it's the first such feature of its kind, and one that police have long been pushing for the Federal Communications Commission to make mandatory. In fact, the debut of Activation Lock precedes a major "Smartphone Summit" between law enforcement officials in San Francisco and New York set to convene on June 13. The forum's goal, according to The Washington Post, is to urge Apple, Google, Samsung, and Microsoft to "create new technology to permanently and quickly disable stolen smartphones, making them worthless to thieves."

The question now is, Will Activation Lock actually prevent phone-related thefts from happening? Probably not at first.

What it will do is slowly but surely alter the psychology of would-be thieves: A phone will be bricked if it's not yours. Hopefully, this will cut down on the increasing number of traumatic and sometimes fatal robberies involving cell phones that happen every single day, especially if, or when, all the major mobile platforms implement similar crime-fighting features. "By rendering phones completely useless, an FCC mandate for kill-switch technology will drastically reduce this major crime problem," says Philadelphia Police Commissioner Charles Ramsey.

Which is why, in my mind, the killer new iOS feature we've all been waiting for is the one that will quietly save lives.