A recent Youtube Web update has added a canvas whenever the seek bar is visible, an HTML5 canvas pops up. This was not asked for and not needed. If you disable canvases for privacy, this will cause a horrific red bad to cover half the screen until you hide the seekbar. Canvases can be used for fingerprinting, which I’m sure Google is doing here.
What exactly is HTML5 canvas image data?
It’s just an API that allows a web page to draw in a box. The problem is, that for a bunch of technical reasons that I’m mostly not aware of, it can be used to fingerprint you.