Surprisingly, the much-depleted federal New Democrats, and especially their still-new leader Avi Lewis, appear to be having an impact on at least some of the Mark Carney Liberals’ policy choices. Lewis’ first public act after becoming leader was to call for a halt to something called “surveillance pricing.” That odd-sounding phrase refers to the retail practice of snooping on a customer’s online presence to tailor a price to that person. For exa…