Both YouTube and Twitch allow you to do non public streams. And someone can get the stream key and stream over you. With the twitch model where stream keys don't get replaced you can imagine a secondary market place selling access to stream content on compromised channels.
Debatable, but historically quite a few consoles and handhelds have been popped wide open by leveraging defects or vulnerabilities in how media is handled. Without looking at an exhaustive list, I believe tif files have claimed the most victims with the next two being split between videos and then media within browsers. I'm aware this is more about out than in, but a gap is a gap and gamers will use whatever they can find.
