The glasses are just a camera. Pretty much any camera can be used for this; Metas glasses are just a bit more discreet than pointing your phone at someone. Cameras are pretty ubiquitous and come in many many form factors, including super small easily hidden forms like clothes pins/buttons.

The real news here:

reverse face search engines like PimEyes and Facecheck ID, as well as people search engines like FastPeopleSearch, CheckThem, and Instant Checkmate.

Can be used to dox people in seconds.