Cloudflare has exactly that: https://blog.cloudflare.com/randomness-101-lavarand-in-production/ https://blog.cloudflare.com/randomness-101-lavarand-in-produ...

Cloudflare has exactly that: https://blog.cloudflare.com/randomness-101-lavarand-in-production/ https://blog.cloudflare.com/randomness-101-lavarand-in-produ... > LavaRand is a system that uses lava lamps as a secondary source of randomness for our production servers. A wall of lava lamps in the lobby of our San Francisco office provides an unpredictable input to a camera aimed at the wall. A video feed from the camera is fed into a CSPRNG, and that CSPRNG provides a stream of random values that can be used as an extra source of randomness by our production servers.