  This essay argues that when measurement processes involve energies of the
order of the Planck scale, the fundamental assumption of locality may no longer
be a good approximation. Idealized position measurements of two distinguishable
spin-$0$ particles are considered. The measurements alter the space-time metric
in a fundamental manner governed by the commutation relations $[x_i\,\,p_j]=
i\hbar\,\delta_{ij}$ and the classical field equations of gravitation. This
{\it in-principle} unavoidable change in the space-time metric destroys the
commutativity (and hence locality) of position measurement operators.
