On the other hand, Meta is one of the very last companies that I would trust to operate a fleet of network connected always-on cameras attached to everyone's faces. The privacy implications are pretty horrifying. Imagine if Meta decided to run facial recognition on-device and upload the results to their advertising services. Your position could be easily tracked any time you walk into the field of view of someone wearing Meta glasses without your consent.
Not to mention for users that choose to use these things voluntarily, you are giving Meta an intimate look into every waking moment of your life. You think data brokers have too much on you now, just wait.
EDIT: Looks like most innocuous comments expressing privacy concerns on this post are getting flagged. That's not how HN is supposed to work, folks.