This is what I found with some legal notes…
https://www.linkedin.com/pulse/can-i-embed-videos-from-other-sites-devin-miller/
" The Appeals court ruled that embedding a video that infringes on copyrighted material is not a violation of copyright law. For example, if you found an episode of The Simpsons on YouTube and embedded it in your blog, you would not be violating any copyright laws. That holds true even if the person who uploaded the video ripped it straight from The Simpsons season 3 DVD. However, the person who uploaded the video is in violation of the law."
This is about YouTube, I can imagine its the same thing at Twitch!
Currently we embed Twitch streams on RaidPal