Separating stalkers from tracking technology.

• Author: Greenberg, Pam
• Position: TRENDS & TRANSITIONS

The electronic devices most of us carry can identify where we are at any moment. Usually, it's a feature we've requested--a navigation app that provides directions, an app such as Foursquare that lets friends know where we are, a taxi app that tells the driver where to pick us up. Parents can keep an eye on their children, caregivers can make sure Alzheimer's patients are safe and businesses can monitor company vehicles.

But stalkers and abusers also are discovering tracking technology, especially as it becomes cheaper and more available. Some stand-alone devices are small enough to be hidden under a car or in the trunk or placed in a backpack or purse. They are marketed as tools to spy on cheating spouses and have pricetags of under $200.

Today, one in four stalking cases involves some sort of technology, and one in 13 involves electronic monitoring or GPS tracking, a U.S. Justice Department survey estimated.

State legislatures are taking action. In July, New York enacted "Jackie's Law" in honor of Jacqueline Wisniewski, whose surgeon ex-boyfriend stalked and killed her in 2012 after putting a GPS device in her car. The law adds unauthorized GPS tracking as a crime under the state's anti-stalking law. "It's appalling that this action alone was not illegal," said Senator Tim Kennedy (D), a sponsor of the legislation. "Survivors of domestic violence are in dire need of this protection, which will ensure law enforcement and prosecutors have the power to intervene in domestic violence cases before it's too late."

At least 10 states prohibit unauthorized tracking. Delaware, Illinois, Michigan, Tennessee and Texas prohibit the secret installation of a tracking device on a vehicle. California, Hawaii, Louisiana, Minnesota and Virginia prohibit placing devices on other movable...