Just four data points from a location-tracking cellphone were enough to reveal the identities of 95 percent of people in a recent study. Is that a problem for you? This new Kickstarter campaign offers a solution: a signal-proof phone case called Off Pocket.

Off Pocket, created by Brooklyn-based technologist Adam Harvey and fashion designer Johanna Bloomfield, blocks your phone's cellular, Wi-Fi, and GPS signals.

Why not just turn the phone off? What appears to be "off" on a phone might not be a pure off state. As Electronic Frontier Foundation technologist Seth Schoen explained to The New York Times, "These modes often allow the device to wake up autonomously if certain conditions are met, such as pressing a certain key or even receiving certain data over the Internet on a wired Ethernet connection." Spooky.