One morning a couple of weeks ago, I handed my iPhone to my wife and asked her to help with a privacy experiment. She would use my handset to track my location for the next few days, and with only the software I already had installed. Like a lot of couples, my wife and I know each other’s phone PINs. So I left her with the device as I walked into our bathroom to take a shower, simulating an opportunity that I figured would present itself daily to snooping spouses.
I’d barely turned on the water before she handed the phone back to me. A few seconds had passed, and she had already configured it to track my location, with no notification that it was now telling her my every move.
I’d embarked on this strange exercise with the blessing of a group of researchers who focus on the scourge of “stalkerware,” a class of spyware distinguished by the fact that it’s typically installed on a target device by someone with both physical access to the phone and an intimate relationship with its owner. Often explicitly marketed as a way to catch a cheating husband or wife in the act, these programs have become a tool of domestic abusers and angry exes—a breed of hacker who often possesses practically zero technical skills but does have plenty of opportunity for hands-on tampering with a victim’s handset. Perpetrators can install these apps, also sometimes known as spouseware, to monitor where their targets go, who they communicate with, what they say, and virtually every other part of their life the phone touches.