I am against this kind of technology because I want to keep my feelings to myself and not letting other people know. It's my decision if I want to keep my feelings from other people and to not let know my true feelings.

This sentence "But in a false smile , the mouth is stretched sideways using the zygomatic major and a different muscle, the risorius. To an expert, faces don't lie; these muscle clues are sometimes used to spot when a smiling"

This sentence tell us how they recognize if they are faking a smile of not or knowing if that person is telling the truth or not. And don't want some technology to know if I'm faking something or not. It's my personal business if I want that. Other people can use that for things but they have to ask for permission because how would you feel if someone found out about your true feeling and it was secret yet someone was snooping around of knowing how you feel.