Tile Inc. urged the Ninth Circuit on Monday to force a proposed class action into arbitration, arguing that customers were adequately notified of its arbitration clause through a mass email even if that message landed in users’ spam folders.

The dispute stems from a lawsuit accusing Tile and its partners of creating Bluetooth tracking devices that can be misused by stalkers. During oral arguments in San Francisco, Tile’s attorney said continued use of the Tile app after the company sent notice of updated terms amounted to customer consent.

The appeal challenges a December 2024 ruling by U.S. District Judge Rita F. Lin, who partially denied Tile’s effort to compel arbitration in a suit brought by Tile users Melissa Broad and Jane Doe.

Tile produces small Bluetooth trackers designed to help locate misplaced items such as keys and wallets. In 2021, the company partnered with Amazon, allowing Tile devices to tap into Amazon’s Sidewalk network, which relies on Bluetooth signals from Echo devices to expand tracking range.

The plaintiffs claim the expanded tracking capability created safety risks and lacked sufficient safeguards to prevent stalking. Their lawsuit alleges negligence, design defects, unjust enrichment, privacy violations and breaches of California law.

Tile sought arbitration in mid-2024, pointing to terms of service agreed to by the plaintiffs in 2021 and 2023, along with later updates. Judge Lin ruled that claims tied directly to the plaintiffs’ own use of Tile products belonged in arbitration but allowed broader claims to proceed in court.

Arguing before the Ninth Circuit, Tile attorney Jeffrey M. Gutkin of Cooley LLP said both plaintiffs accepted arbitration by continuing to use Tile’s service after receiving an October 2023 email announcing updated arbitration terms.

Gutkin relied on Ninth Circuit precedent, including Mohamed v. Uber Technologies Inc., arguing that similar arbitration provisions had already been upheld. He also said Tile’s earlier terms incorporated American Arbitration Association rules, which typically leave questions of arbitrability to arbitrators.

Plaintiffs’ counsel David F. Slade of Wade Kilpela Slade LLP pushed back, arguing there is no proof one plaintiff received the email and that the other never saw it because it went to spam. He said Tile’s terms did not clearly delegate arbitrability decisions away from federal courts.

Slade also disputed Tile’s reading of Brennan v. Opus Bank, saying incorporation of arbitration rules does not automatically shift arbitrability decisions when the same agreement also directs disputes to California courts.

Members of the appellate panel expressed skepticism toward both sides. U.S. Circuit Judge Jacqueline H. Nguyen noted that she personally receives thousands of spam emails and rarely checks them.

“I get thousands of junk emails and I have to confess I don’t often check my junk email box,” she told Tile’s counsel, asking for authority showing that spam-folder delivery still counts as notice.

Gutkin cited a 2024 California district court ruling in Ghazizadeh v. Coursera Inc., which found that mass emails announcing arbitration provisions could provide sufficient notice when users continued using a service without objection.

The panel took the case under submission.

The appeal is Shannon Ireland-Gordy et al. v. Tile Inc. et al., case number 25-403, in the U.S. Court of Appeals for the Ninth Circuit.