Concerns are mounting as more videos emerge of people being filmed in public without their knowledge or consent. In several cases, women have discovered clips of themselves circulating online only after the videos gained traction, sometimes attracting abuse. Because filming in public spaces is generally legal, those affected often have little legal recourse.

Meta’s Ray-Ban smart glasses, currently the dominant product in the market, feature discreet cameras embedded into the frame, small speakers in the arms, and voice- or touch-activated recording functions. The design makes it difficult for bystanders — and at times even wearers — to know when recording is taking place.

The glasses are produced in partnership with EssilorLuxottica and have become the best-selling smart glasses globally, accounting for an estimated four-fifths of all sales in the category. Meta says more than seven million pairs have been sold so far.

Speaking earlier this year, Meta chief executive Mark Zuckerberg described the glasses as among the fastest-growing consumer electronics products in history.

However, the technology has also drawn scrutiny over how recorded footage is handled. Lawsuits filed in the United States allege that some users were unaware that videos captured by their glasses were reviewed by human moderators as part of AI training processes. Meta has said such possibilities are outlined in its terms of service.

Despite the controversy, other technology giants are preparing to enter the market. Apple is reportedly developing its own version of smart glasses, while Snap plans to release an updated model later this year. Google is also expected to revisit the category, more than a decade after abandoning Google Glass amid privacy backlash.

Industry analysts predict that as many as 100 million people could be using smart or AI-powered glasses within the next few years. That prospect has raised concerns about enforcement of existing rules banning recording in sensitive spaces such as hospitals, cinemas, courtrooms and bathrooms.

Privacy experts warn the challenge will intensify if features such as facial recognition are introduced, potentially allowing wearers to identify strangers instantly while recording them.

Meta markets its glasses under the slogan “Designed for privacy, controlled by you”, advising users not to record people who object and to switch the device off in sensitive environments. Critics say those guidelines are often ignored, particularly as the glasses are increasingly used to film pranks or unsuspecting members of the public.

While some early adopters praise the convenience of hands-free calls, music and photography, many observers believe the technology risks repeating the mistakes that doomed earlier attempts.

As one former Meta researcher told reporters, devices that quietly turn everyday eyewear into cameras are likely to face growing public resistance — no matter how popular they become.