[ProtectOurFreedom]

"why not just use some CCTV feed data from some busy street scene?"

There have been many such attempts to use chaotic and seemingly random physical processes to generate the seed for random number generators. The article says researchers have "...looked practically everywhere for chaotic phenomena that can't be predicted or manipulated. They have listened to the racket of electrical storms, captured pictures of raindrops on glass, and played with the tiniest particles in the known Universe."

Wiki --> "Many natural phenomena generate low-level, statistically random "noise" signals, including thermal and shot noise, jitter and metastability of electronic circuits, Brownian motion, atmospheric noise. Researchers also used the photoelectric effect, involving a beam splitter, other quantum phenomena, and even the nuclear decay (due to practical considerations the latter, as well as the atmospheric noise, is not viable)."

How about Cosmic Rays? Using cosmic rays to generate and distribute random numbers and boost security for local devices and networks

[SaveFerris]

[The article says researchers have "...looked practically everywhere for chaotic phenomena]

Might I make a suggestion?

[Sarcazmo]

I should have known someone thought of that already.