True randomness, but ....
as any claim for random number generation, this one is based on underlying assumptions about physical reality and our understanding thereof. You can always postulate hidden variables that would destroy the randomness (when we eventually understand and predict those hidden variables).
Alternatively, you can trust our current understanding of physics and build much simpler quantum detection devices. Avalanche amplification of tunneling events (cf. http://iank.org/trng.html or similar) is a sensible approach. The devil, of course, is in the details of the implementation.
Biting the hand that feeds IT
