San Francisco has become the first US city to ban police and other public departments from using facial recognition software.
The move comes as the rapidly developing technology has alarmed privacy and civil rights campaigners.
The city of Oakland, also in California, is considering a similar ban.
Aaron Peskin, who sits on the San Francisco board of supervisors, said: “This is really about saying ‘we can have security without being a security state. We can have good policing without being a police state’.
“And part of that is building trust with the community based on good community information, not on Big Brother technology.”
The ban is part of wider legislation that requires city departments to establish use policies, and obtain board approval, for surveillance technology they are using or plan to buy in future.
Several other local governments require departments to disclose and seek approval for surveillance technology.
Mr Peskin said it is unclear how many San Francisco departments are using surveillance and for what purposes.
He highlighted that there are valid reasons, such as for number-plate readers, body cameras and security cameras.
Mr Peskin added that the public should know how the tools are being used or if they are being abused.
The ban applies to police and other city departments, and does not affect use of the technology by the federal government at airports and ports.
Nor does it limit personal or business use.
San Francisco supervisor Catherine Stefani, who was the only one to vote against the ban, said: “I worry about politicising these decisions.”
The Information Technology and Innovation Foundation, a non-profit think tank based in Washington DC, issued a statement criticising San Francisco for considering the facial recognition ban.
It said advanced technology makes it cheaper and faster for police to find suspects and identify missing people.
Daniel Castro, the foundation’s vice president, said it was “silly” to compare surveillance usage in the United States with China.
He added that this was because the US has constitutional prosecutions while China does not.
Mr Castro said: “In reality, San Francisco is more at risk of becoming Cuba than China.
“A ban on facial recognition will make it frozen in time with outdated technology.”
San Francisco’s police department stopped testing facial recognition technology in 2017.
A representative at Tuesday’s board meeting said the force would need two to four additional employees to comply with the legislation.
Privacy campaigners have been at loggerheads with those in favour of the technology at several heated hearings in San Francisco.
Those who support the ban say the technology is flawed and a serious threat to civil freedoms, especially in a city that cherishes public protest and privacy.
The campaigners fear people will no longer be able to visit a shopping centre, park or school without being identified and tracked.
But those in favour of the technology say police need all the help they can get, especially in a city that hosts high-profile events and has high rates of property crime.
Meredith Serra, a member of resident public safety group Stop Crime SF, believes it is unreasonable for people to expect privacy in a public place.
She said: “To me, the ordinance seems to be a costly additional layer of bureaucracy that really does nothing to improve the safety of our citizens.”