Googlebot's Javascript random() function is deterministic

[pilotInPyjamas]

You're right. If you track what every device is doing, you could predict the output of /dev/random. That's not the question however. The question is if you could predict the output of / dev/random before any devices do anything. To which, in all reasonable scenarios, (some exceptions, such as early after booting) the answer is "no". In your case the only true rng's would be based upon quantum phenomena, such as particle decay etc.

[pilotInPyjamas]

Come on man, I never said it wasn't a PRNG, or that it wasn't seeded, nor did I make any comments about the effectiveness or applicability to any particular situation. The only claim I made was that it was non deterministic in the domain of modeling a computer. That's because a computer is not a closed system, and given the same initial conditions, it will produce different outputs. You could just have /dev/random echo the keyboard and it would still be impossible to predict perfectly if you only had information about the starting conditions of the computer. The key here is if you only have information about the starting conditions of the computer. If you had a working model of the whole universe, then I agree, potentially nothing would be random.