US News 
May 2, 2013
Worried about drones spying on you? Soon, a device might be able to send you text and email alerts that let you know when a drone is nearby.
A Washington, D.C.-based engineer is working on the “Drone Shield,” a small, Wi-Fi-connected device that uses a microphone to detect a drone’s “acoustic signatures” (sound frequency and spectrum) when it’s within range.
The company’s founder, John Franklin, who has been working in aerospace engineering for seven years, says he hopes to start selling the device sometime this year. He is using the Kickstarter-like IndieGoGo  to finance the project.
The device will cost $69 and will be about the size of a USB thumb drive. It will use Raspberry Pi – a tiny, $25 computer – and commercially available microphones to detect drones. He says he imagines that people will attach the Drone Shield to their fences or roofs to protect their home from surveillance.
“People will get the alert and then close their blinds,” Franklin says.