Your phone isn't secretly listening to you, but the truth is more disturbing

> "Apps were automatically taking screenshots of themselves and sending them to third parties. In one case, the app took video of the screen activity and sent that information to a third party.”

> Out of over 17,000 Android apps examined, more than 9,000 had potential permissions to take screenshots. And a number of apps were found to actively be doing so, taking screenshots and sending them to third-party sources.

Which permission is that, and how do you detect which apps are doing that and stop them?

There is a permission to record the screen. It requires user consent and there's an icon in the status bar while it's being used. It's impossible to use this covertly.

What I believe the article is speaking about, is an app taking screenshots of its own windows. This is obviously possible and obviously requires no permissions whatsoever. Just make a screen-sized bitmap and do

    getWindow().getDecorView().draw(new Canvas(bitmap));

It does sound believable that third-party advertising/marketing/tracking SDKs, which many apps are chock full of, could be doing this.

> It's impossible to use this covertly.

*Unless there's a zero-day that allows it.

If you're going to exploit a privilege escalation vulnerability from your app, why not just grab the most interesting parts of the /data partition while you're at it?