When federal authorities recently arrested a man for making and marketing a so-called "stalker app," Cindy Southworth of the National Network to End Domestic Violence was thrilled.
"My gut reaction was, 'yippee!'" Southworth told 48 Hours' Crimesider. "One down, hundreds to go."
Hammad Akbar, a Pakistani native and the CEO of the company that makes StealthGenie, is accused "selling a mobile spyware application that illegally intercepts wire and electronic communications made using smart phones," according to the federal complaint.
Marketed to people who suspect their significant other is cheating, StealthGenie boasted that it is "100% undetectable" once uploaded to a person's phone, and immediately starts allowing the user to monitor the communications from that phone via an online server, the complaint states. But according to Southworth and others, these apps make illegal activities - like stalking - dangerously easy.
"We try to minimize the victim's exposure to the stalker, and technology like this thwarts it," says Michele Archer, a director at the victim's advocacy group Safe Horizon. "You can be a living room stalker. It's a lot less effort."
Archer says Safe Horizon is seeing more and more women who say their abuser or stalker seems to know where they are all the time, and worry they may be reading their emails or tracking them via the GPS locator on their mobile phone or a vehicle security system like OnStar. This can pose a particular problem for victims who share a mobile plan with their abuser.
Sen. Al Franken (D-Minn.) has been pressuring federal agencies to investigate the makers of these spyware apps since 2011. In June 2014, Congress held a hearing on his bill seeking to outlaw apps that allow a user to monitor a person's location via GPS tracking and read their text messages or listen to their voicemails.
"My bill would shut down these apps once and for all," Franken told the Senate's Judiciary Subcommittee on Privacy, Technology and the Law.
According to a National Network to End Domestic Violence survey, 72 percent of programs serving domestic violence and stalking victims in the U.S said their clients had reported being tracked using GPS devices. And both Archer and Southworth say that telling victims to just turn off their phones may cause as many problems as it solves: the lack of a mobile phone makes it difficult to call for help, or locate nearby services if you are in danger.
"Domestic violence is about keeping the victim under your thumb," says Southworth. And what better way to keep someone under your thumb than to install a difficult-to-detect application on their phone that will tell you where they are at all times.
"Imagine the trauma of surviving domestic and sexual violence," testified Anoka County Minnesota Detective Brian Hill at June's Senate subcommittee hearing.
"Now add cyberstalking to that trauma. Stealth stalking apps endanger domestic violence victims' safety, financial stability, and social well-being."
After Akbar's arrest on Sept. 30, Sen. Franken issued a statement urging fellow lawmakers to act on his bill, called the Location Privacy Act of 2014.
"Currently there is no federal legislation banning the secret collection of location data," he said. "My bill would finally put an end to GPS stalking apps that allow abusers to secretly track their victims."
While surreptitious location tracking remains legal, Safe Horizon's Archer, herself a survivor of stalking, says she advises victims who suspect they're being tracked or spied on to turn their phones completely off when they are visiting places they wouldn't want their abuser to know about - a battered women's shelter, for example, or an attorney's office.
Archer also emphasizes the importance of keeping a record of the abuser's behavior, including saving messages and logging dates and times when he or she showed up at a place you didn't tell anyone you were going to visit.
"If you can show a pattern of behavior that would give a reasonable person fear," says Archer, police can take action.