CDT Files Amicus Briefs on Location Data, Teen Online Rules and Section 230

Location data and the Fourth Amendment

Several of the briefs concern digital searches. In New Jersey v. Bryant, filed with the New Jersey Supreme Court on September 23, 2026, CDT calls on the court to rule that a tower dump warrant was an unconstitutional general warrant. According to CDT, tower dumps collect location data for all cell phones that ping off a cell tower or a set of towers, and the warrant in question was needlessly broad.

CDT also filed in Chatrie v. United States, a geofence warrant case. Its February 27, 2026 brief to the Supreme Court, submitted with the Brennan Center for Justice, Defending Rights & Dissent and the Surveillance Technology Oversight Project, argued that electronic location data is protected by the Fourth Amendment's warrant requirement. CDT says the Court ruled that the Fourth Amendment protected all cell phone location information, but sent the case back to the Fourth Circuit to assess the geofence warrant. In its September 4, 2026 brief on remand, CDT argues the geofence collected far beyond the necessary time and area, and warns that approval could open the door to other "reverse warrants", such as reverse keyword and AI-prompt warrants.

Youth online safety laws and the First Amendment

CDT filed in three cases challenging state laws aimed at young people online.

• Meta Platforms v. Bonta (Ninth Circuit, September 15, 2026): submitted with the Electronic Frontier Foundation and Wikimedia Foundation, the brief challenges California's SB 976. CDT argues that restricting teenagers' access to personalized recommendation systems burdens their First Amendment rights, and that platform decisions about what to recommend are protected editorial judgments. It says states can address addictive design and private surveillance through narrower approaches, including stronger privacy protections and tools that give young people more control.
• NetChoice v. Weiser (Tenth Circuit, July 17, 2026): CDT supports a challenge to a Colorado law that compels social media platforms to send state-dictated messages through recurring notifications about risks of harm to youth. The brief argues the law fails under strict scrutiny or the more deferential Zauderer standard, while saying better-crafted transparency mandates are permissible.
• Students Engaged in Advancing Texas v. Paxton (Fifth Circuit, June 24, 2026): submitted with the Internet Society and New America's Open Technology Institute, the brief opposes Texas's App Store Accountability Act. The law requires app stores to verify all users' ages and, for minors, to obtain parental approval for every download. CDT says the law should fail under either standard of scrutiny and cites its own research showing parents and children are skeptical of age verification. It suggests Texas could have used a voluntary age signaling system instead.

Section 230, encryption and AI

In Patterson v. Meta, filed with the New York Court of Appeals on August 27, 2026 together with the Foundation for Individual Rights in Education, CDT argues that Section 230 protections are essential to online expression and extend to automated systems that rank and order content. It also argues that product liability claims are not automatically outside Section 230, and that courts must ask whether a claim seeks to hold a provider liable as a publisher of third-party content. CDT says the appeal follows a lower court victory that cited its earlier brief in holding that content-ranking algorithms are protected editorial activity.

In WhatsApp v. NSO Group (Ninth Circuit, May 20, 2026), CDT urges the court to affirm a permanent injunction barring NSO from technology that interacts with WhatsApp's platform, including the Pegasus spyware. CDT says strong end-to-end encryption is a cornerstone of both human rights and national security.

CDT also filed in Anthropic PBC v. Hegseth (D.C. Circuit, March 16, 2026), with the ACLU, supporting Anthropic's challenge to the Department of Defense designation of the company as a "supply-chain risk." According to CDT, the designation was retaliation for Anthropic refusing to accept DoD use of its AI systems for fully autonomous lethal weapons or domestic mass surveillance. CDT's brief stresses the need to address domestic mass surveillance, which it says would be significantly exacerbated by AI tools. The source text is cut off before the rest of this entry.

What it means

The list shows where CDT is pressing courts on how constitutional protections apply to digital data and platform design. Across the cases, its positions are consistent: location data deserves Fourth Amendment protection, and recommendation and ranking systems are tied to speech rights. It also argues that lawmakers have narrower, privacy-focused options for protecting young people online. The outcomes of these cases remain with the courts, and the source reports only CDT's own arguments and filings.