[Aquinax]

https://www.youtube.com/watch?v=6PfIch6no5I

Seems to be protected content. I wanted to download and save it for myself. Thank you.

[lajvguy]

Doesn't look protected. I can download using Video DownloadHelper (Firefox extension).

[confused.com]

https://github.com/rg3/youtube-dl/blob/master/README.md

youtube-dl.exe -v -F --no-check-certificate https://www.youtube.com/watch?v=6PfIch6no5I