As reported by Gizmodo, researchers Elleen Pan, Jingjing Ren, Martina Lindorfer, Christo Wilson, and David Choffnes studied more than 17,000 apps, including ones from Facebook and those that send information to Facebook, to see if any of them were capturing audio via Android phone microphones. As you might have guessed, the researchers found no evidence of apps activating the microphone or sending audio on the sly.

They did, however, discover something disturbing: some apps were sending phone screen recordings out to third parties. In one case, they found that GoPuff, a junk food delivery app, was sending screen shots and video recordings of user screens to analytics company, AppSee. That might make sense in our highly connected world, but this behavior was not disclosed in GoPuff's privacy policy (the company has since added a line to cover the usage).