I just tested using the Snipping tool with a Netflix movie playing and got these results:
Windows 10, Firefox 125.0.1 - video is black but you can see the netflix title and seekbar in Snipping tool
Windows 10, Chrome 123.0.6312.124 with graphics acceleration off - video is visible and captured in Snipping tool
antique Windows 7, Firefox 115.10.0 0 video is visible and captured in Snipping tool.
So it is possible to screen capture from Netflix but I can see it being a problem depending on your browser and OS.
Windows 10, Firefox 125.0.1 - video is black but you can see the netflix title and seekbar in Snipping tool
Windows 10, Chrome 123.0.6312.124 with graphics acceleration off - video is visible and captured in Snipping tool
antique Windows 7, Firefox 115.10.0 0 video is visible and captured in Snipping tool.
So it is possible to screen capture from Netflix but I can see it being a problem depending on your browser and OS.