People, if you're going to wait hours for your iPhone 4 or iPad 2, don't flaunt them on the subway, because thieves love ripping them out of unsuspecting tecno-savvy straphangers' hands. According to the Wall Street Journal, "This year, there were 311 grand larcenies on the subway through the end of March, an 18% increase over the same period in 2010" and it's "largely driven by the increasing theft of smartphones, especially Apple's iPhone 4, said Raymond Diaz, chief of the New York City Police Department's transit bureau." Diaz told the MTA, "We've been seeing an incredible trend of young people snatching those cellphones."

Diaz also explained which lines are where most smartphone and tablet thefts take place: It's the 4, 5, and 6 in Manhattan, the J and L in Brooklyn and the M, R, and 7 lines in Queens. Helpful tip: People using their devices near the train doors are obviously sweeter targets, because a thief can just grab and leave as the subway cars go. Another tip: Even if someone begs to hold your iPhone, iPad, whatever, don't let them—unless you're willing to part with it permanently, as illustrated in this cautionary tale:

Williamsburg musician Nate Smith recently boarded the G train to meet friends in Carroll Gardens, Brooklyn, while listening to the minimalist D.J. Ricardo Villalobos on his iPod. A teenager, who was with a group of friends, sat down next to him and asked Mr. Smith if he was listening to an iPod, Mr. Smith said.

The teenager asked if he could see it. At first, Mr. Smith, 34 years old, refused. But as the teenager badgered him, Mr. Smith relented. Meanwhile, the train was pulling into the next stop.

"I let him hold it. I don't know why I did," Mr. Smith said. "He got up and started to walk away."

Mr. Smith shouted after him, but the teen ignored him and got off the train with his friends. Mr. Smith said he called police but declined to file a report.

(This applies to bikes as well.)

The NYPD initially suspected that the phones were being stolen for personal use, but it turns out many are being resold. So now cops are buying phones for sting operations. And when the iPhone first came out, Police Commissioner Ray Kelly said the gadget was sparking a rise in the number of young muggers out there.