The U.S. Congress on Thursday passed legislation that would allow U.S. Supreme Court justices and federal judges to shield their personal information from being viewed online in response to a rising number of threats targeting them.

The Daniel Anderl Judicial Security and Privacy Act, named for the son of a federal judge who was fatally shot in 2020, was attached to the annual must-pass defense policy bill that the Senate endorsed 83-11.

The defense bill passed the U.S. House of Representatives last week and now heads to President Joe Biden for his signature.

The judicial security measure, which the federal judiciary backed, had long languished in Congress before its supporters were able to tack it on to the National Defense Authorization Act.

The measure remained in the 4,000-plus page defense bill despite criticism from public interest groups who say it could chill free speech and undermine efforts to scrutinize judges’ conflicts of interest.

The bill was named for the 20-year-old son of U.S. District Judge Esther Salas, who was shot and killed at her home in New Jersey by a disgruntled lawyer posing as a deliveryman in an attack in July 2020 that also injured the judge’s husband.

The attack highlighted the growing number of threats targeting judges. The U.S. Marshals Service said judges were subject to 4,511 threats and inappropriate communications in 2021, up from 926 in 2015.

The measure would make it illegal for commercial data brokers to knowingly sell, license or purchase addresses, phone numbers, Social Security numbers and other personally identifiable information of judges or their immediate family.

Government agencies could not publicly post judges’ personal information, and the bill bars other businesses and people from posting their information online if a judge requests they not do so. Violators could face lawsuits by the judiciary and financial penalties.

The bill contains exemptions, including for journalists using information for news. Sponsors of the bill, including Senator Bob Menendez, a New Jersey Democrat, say it is narrowly tailored to protect judges.

But critics including the groups Demand Justice and Fix the Court say the bill could unconstitutionally restrict discussion about judges’ conflicts of interests and obscure sources of information about them and their families.

They say its provisions even allow for demands to remove information concerning the employers of Supreme Court justices’ spouses, hindering efforts to determine if a justice should be recused from a case.

The issue of conflicts involving justices’ spouses has been central to a debate over whether conservative Supreme Court Justice Clarence Thomas should recuse himself from cases concerning the Jan. 6, 2021, attack on the U.S. Capitol because his wife, Ginni Thomas, advocated for overturning the 2020 presidential election.