Could your smartphone be listening in on your life? If you download mobile apps without much care for their permissions requests, you might not ever know. The privacy threat is so significant though, that the Federal Trade Commission has stepped in and warned us to be aware of it.
On Thursday, the FTC sent a letter to a dozen app developers warning them against their use of "audio beacons", which listen in on the environment and pick up hidden noise signals from TV shows. This is made possible with technology from an Indian company named Silverpush, and in effect it lets the app figure out what you're watching, because it has the ability to listen in at will. The app would also be able to tell if you completed a show or stopped it half-way through - this type of information is gold for marketers.
It's important that the FTC issued this warning before audio beacons become an even bigger problem, but it's unfortunately keeping quiet on which are the guilty, offending apps. However, we can be assured that they are fairly mainstream, as the FTC was able to source them easily enough. If you are concerned about this kind of app behavior, you could review the permissions each app on your phone has access to, and if any app that doesn't require microphone access has it, you could very well be looking at one of these guilty apps.
If you pay for an app, it's unlikely that there will be hidden features like this, but when an app is cost-free, there are immediate reasons to be skeptical. A couple of years ago, we reported on a spying issue that was discovered with a very popular free flashlight app on Google's Play Store (what is it with flashlight apps?). A great rule of thumb to abide by is that if an app is free, and isn't developed by some recognizable, trusted company you should tread lightly, and watch the permissions carefully.
The FTC's letter explicitly states that the developers in question published their apps on Google Play, so this seems to affect only Android at the current time. If the issue becomes big enough, Google could perhaps implement an extra layer of protection by warning people the first time a newly-installed app is opened if it has access to either the camera or the microphone. If you downloaded a flashlight app and received that kind of warning, it should obviously be a red flag, and a great reason to make a b-line to the uninstall button.