"Anyone who considers arithmetical methods of producing random digits is, of course, in a state of sin." (von Neumann)
Generating truly random numbers is a merely technical problem. There's no fundamental limitation like Heisenberg's uncertainty (well, our electronics hasn't yet reached that state where this would matter). Faulty electronics introduces unwanted correlations. Quantum computers *might* solve this problem once and forever.
Also, one shouldn't mix up two things: a single realization of a random process (which can be perfectly random) and the underlying statistical distribution (which is deterministic and can be quantified numerically or analytically).
Sorry for nerd speech.