The most talked-about product from Google's developer conference earlier this week -- Duplex -- has drawn concerns from many . At the conference Google previewed Duplex, an experimental service that lets its voice-based digital assistant make phone calls and write emails. In a demonstration on stage, the Google Assistant spoke with a hair salon receptionist, mimicking the "ums" and "hmms" pauses of human speech. In another demo, it chatted with a restaurant employee to book a table. But outside Google's circles, people are worried; and Google appears to be aware of the concerns . From a report: