  BosonSampling is a quantum mechanical task involving Fock basis state
preparation and detection and evolution using only linear interactions. A
classical algorithm for producing samples from this quantum task cannot be
efficient unless the polynomial hierarchy of complexity classes collapses, a
situation believe to be highly implausible. We present method for constructing
a device which uses Fock state preparations, linear interactions and Gaussian
continuous-variable measurements for which one can show exact sampling would be
hard for a classical algorithm in the same way as Boson Sampling. The detection
events used from this arrangement does not allow a similar conclusion for the
classical hardness of approximate sampling to be drawn. We discuss the details
of this result outlining some specific properties that approximate sampling
hardness requires.
