California has become the first state to prohibit most law enforcement officers, including federal immigration agents, from concealing their faces during official duties, under a law signed by Gov. Gavin Newsom on Saturday.

The legislation is a response to the recent immigration raids in Los Angeles, during which federal agents wore masks while conducting mass arrests. These actions led to widespread protests and resulted in President Donald Trump deploying National Guard troops and Marines to the area.

Newsom made the announcement in Los Angeles, where he signed the bill alongside state lawmakers and members of the immigrant community, emphasizing that California is distinctive with 27% of its residents being foreign-born.

“We celebrate that diversity. It’s what makes California great. It’s what makes America great. It is under assault,” he said.

The Democratic governor criticized the use of masked agents lacking identification or badge numbers, apprehending individuals on the streets, and stated that the state is resisting such practices.

“These policies have terrifying effects across this city, our state, and our nation,” Newsom remarked. “It’s like something out of a dystopian sci-fi film—unmarked cars, masked individuals, people literally disappearing. There’s no due process, no rights, which should not happen in a democracy where rights are integral. Immigrants have rights, and we are here to assert and defend those rights.”

But it’s unclear how — or whether — the state can enforce the ban on federal agents.

Officials from the Trump administration have justified the use of masks, citing that immigration agents face increasing levels of harassment both publicly and online while they enforce mass deportation policies. They argue that disguising their identities is crucial for the protection of the agents and their families.

DHS official criticizes California law

Tricia McLaughlin, Homeland Security assistant secretary for public affairs, called it “despicable and a flagrant attempt to endanger our officers.”

“Sanctuary politicians’ rhetoric comparing ICE to “secret police” — likening them to the Gestapo — is diabolical,” she said via email. “While our federal law enforcement officers are being assaulted by rioters and having rocks and Molotov cocktails thrown at them, a sanctuary politician is trying to outlaw officers wearing masks to protect themselves from being doxxed and targeted by known and suspected terrorist sympathizers.”

The men and women of federal immigration agencies put their lives on the line to arrest violent criminal illegal aliens, she said, and rhetoric like Newsom’s has contributed to a surge in assaults.

Newsom countered that concerns about doxing, or publishing agents personal information online, are unfounded and unproven.

“There’s an assertion that somehow there is an exponential increase in assaults on officers, but they will not provide the data,” he said. “All they have provided is misinformation and misdirection.”

The new law prohibits neck gaiters, ski masks and other facial coverings for local and federal officers, including immigration enforcement agents, while they conduct official business. It makes exceptions for undercover agents, medical masks such as N95 respirators or tactical gear, and it does not apply to state police.

Other states consider similar measures

Democrats in Congress and lawmakers in several states, including Tennessee, Michigan, Illinois, New York, Massachusetts, and Pennsylvania, have also introduced similar proposals calling for mask bans.

The Department of Homeland Security said it sent letters Friday to the attorneys general in California, Illinois and New York reinforcing previous instructions that the Democratic-led states honor detainers from the U.S. Immigration and Customs Enforcement for “criminal illegal aliens within their jurisdictions.” DHS said in a statement Saturday that if the states fail to comply, it would pursue “all appropriate measures to end their inadvisable and irresponsible obstruction.”

Proponents of the California law said it is especially needed after the Supreme Court ruled this month that the Trump administration can resume its sweeping immigration operations in Los Angeles. The law aims to boost public trust in law enforcement and stop people from impersonating officers to commit crimes, supporters said.

Constitutional law expert Erwin Chemerinsky at the University of California, Berkeley, also defended the legislation. Federal employees still have to follow general state rules “unless doing so would significantly interfere with the performance of their duties. For example, while on the job, federal employees must stop at red lights,” he wrote in an opinion piece for the Sacramento Bee.

The increase in high-profile immigration enforcement was already contentious between those opposed to the actions of Trump’s administration and those in support of them. The sight of masked agents carrying it out is creating a whole new level of conflict.

Another new law covers schools and health care facilities

Newsom also signed legislation Saturday preventing immigration agents from entering schools and health care facilities without a valid warrant or judicial order and requiring schools to notify parents and teachers when immigration agents are on campus.

Assemblymember Al Muratsuchi, D-Torrance, said “students cannot learn if they live in fear of being deported. The California Safe Haven Schools Act is a clear message to Donald Trump: ‘keep ICE out of our schools.’”

Earlier this year the Legislature also authorized giving $50 million to California’s Department of Justice and other legal groups, which has resulted in more than 40 lawsuits against the Trump administration.