While GPU is not suitable for tasks where the domain 
has to be
covered entirely, it could work for tasks where the analysis of big parts of it suffices.
Having multiple answers to the same request is not that bad: available computing power is amazing. In November 2003, Seti@home crunched all available data and is now reprocessing data again; the telescope does not record enough data, although a minute of sky observation turns into 10 hours of Fast Fourier transform analysis.
Additionally, people might compute wrong results intentionally, but their efforts will disappear in random noise due to the nature of Monte Carlo computations, because results will be computed multiple times by different users.