  We present and discuss a master equation blueprint for a generic class of
quantum measurement feedback based models of friction. A desired
velocity-dependent friction force is realized on average by random repeated
applications of unsharp momentum measurements followed by immediate
outcome-dependent momentum displacements. The master equations can describe
arbitrarily strong measurement-feedback processes as well as the weak
continuous limit resembling diffusion master equations of Caldeira-Leggett
type. We show that the special case of linear friction can be equivalently
represented by an average over random position measurements with squeezing and
position displacements as feedback. In fact, the dissipative continuous
spontaneous localization model of objective wavefunction collapse realizes this
representation for a single quantum particle. We reformulate a consistent
many-particle generalization of this model and highlight the possibility of
feedback-induced correlations between otherwise non-interacting particles.
