The variety of devices available on the market surpasses your imagination. Meta's glasses use the same cameras that may be embedded elsewhere in hats and clothing. There are smaller and larger cameras. Meta's glasses simply provide a single person with real-time operational feedback. Whoever is spying usually already knows what they are after. I can't grasp why people are not frightened by the fact that their information can be so easily accessed, yet they are concentrating on some specific device (yes, with some additional benefits for the user, though it's not the only device of its kind).