[danShumway]

This is a complete sidenote, but I don't understand why Firefox's Canvas controls don't affect WebGL.

Firefox has per-site settings for whether the canvas should be accessible which are very useful, but they don't have per-site settings for WebGL, it's either on or off for the entire profile. Which kind of defeats the point of Canvas blocking since (at least last time I checked) WebGL fingerprinting is possible regardless of whether Canvas can be read from.

I'm sure there's some technical reason, but it really seems like turning Canvas reads off for a site should also turn off WebGL.

[cpeterso]

Here is a Firefox bug report suggesting a per-site permission for WebGL: https://bugzilla.mozilla.org/show_bug.cgi?id=1694456

There's been no Mozilla comments on the bug yet. Perhaps so many sites use WebGL that the user would be pestered with too many permission prompts?