This type of theft is called "sliding" and, according to a recent ABC News report, it's on the rise.
It's quite simple. Usually occurring at gas stations, thieves lie in wait as unsuspecting car owners fill up. They case a car to see if it is unlocked. If there are any valuables within reach, and they "slide" under the view of the car's owner and grab any valuables they see on the front seat--purses, phones, computers, tablets. It's called "sliding" because of the way the thieves slide in below the eye level of the door.
"They're not looking for a confrontation," Houston police officer Jim Woods told ABC News. "They just want the property, because they know it's being left abandoned and you're not paying enough attention." It's happens quickly. The thieves typically hover at a gas station looking for just the right prey. The whole act takes a few seconds after they pull up to the target car.
How can you prevent becoming a victim of a "slider?" Police say that you should always take your purse or wallet with you to the pump or, if you have to leave things in the car, make sure to lock up. "A vehicle is not a secure location for your property," a police official told CBS New York. Never leave your car unlocked if the pump is filling your tank while you go into the gas station to use the bathroom or to shop in the convenience store.