CNN Business  — 

The city of Portland, Oregon, on Wednesday banned the use of facial-recognition technology by city departments — including local police — as well as public-facing businesses such as stores, restaurants and hotels.

Portland joins a growing number of places in the United States, such as San Francisco, Oakland, and Boston, that have outlawed city use of the surveillance technology, which is meant to identify a person from an image of their face. But its decision to prevent both local government and businesses from employing the technology appears to be the most sweeping ban yet by an individual city.

Facial recognition technology has grown in prevalence — and controversy — in recent years, popping up everywhere from airport check-in lines to police departments and drugstores. Yet while it could add a sense of security and convenience for businesses that roll it out, the technology has been widely criticized by privacy advocates for built-in racial biases and potential for misuse.

These worries were clearly on the minds of city council commissioners who voted unanimously for the ban. In addition to halting city use of the surveillance technology, the new rule prevents “private entities in places of public accommodation” in Portland from using it, too, referring to businesses that serve the general public — a grocery store or a pizza place, for instance. It does not prevent individuals from setting up facial-recognition technology at home, such as a Google Nest camera that can spot familiar faces, or gadgets that use facial-recognition software for authenticating users, like Apple’s Face ID feature for unlocking an iPhone.

While facial-recognition technology could help with tasks ranging from solving crime to checking student attendance at school, it comes with fundamental privacy issues. Artificial intelligence researchers and civil rights groups, such as the American Civil Liberties Union, are also worried about accuracy and bias in facial-recognition systems. They’re concerned that they are not as effective at correctly recognizing people of color and women (one reason for this may be that images used to train the software may be disproportionately male and white).

Portland Mayor Ted Wheeler expressed these worries, along with the concern that facial-recognition technology could be used to surveil protestors. Protests have been ongoing in the city since the death of George Floyd in late May.

“Technology exists to make our lives easier, not for public and private entities to use as a weapon against the very citizens they serve and accommodate,” he said.

Because no federal guidelines exist to limit or standardize the use of such surveillance technology, and few state rules are in place, municipalities are left to decide for themselves what, if anything, to do to control its use. In the case of Portland, the prohibition begins immediately for Portland’s city government, and on January 1 for private uses of facial recognition technology that are no longer allowed under the rule.

In a statement, the ACLU of Oregon voiced support for the new rules, writing that prohibiting the technology “is necessary and prudent to protect the interests, privacy, and safety of individuals and our communities.”