[dharmab]

It's already trivially easy to fingerprint a user in about a dozen other ways via:

User Agent String (being fixed soon by the Chrome team)

HTTP_ACCEPT headers

Browser plugin metadata

Time zone

System fonts

Supercookies

Canvas and WebGL fingerprinting

AudioContext

Device CPU and memory

What's one more bit of information?

[account42]

Many of these should also not be exposed to websites without explicit authorization.