Writing for a unanimous panel, Circuit Judge Barbara Lagoa held that the district court erred in dismissing claims brought by Frida Kahlo Corporation and Frida Kahlo Investments, S.A. against Mara Cristina Teresa Romeo Pinedo and Familia Kahlo S.A. de C.V. Circuit Judges Luck and Abudu joined the opinion.

The plaintiffs, which say they hold the rights to the Frida Kahlo name and marks under a 2005 assignment, sued in 2022 after the defendants sent letters to the plaintiffs' Florida licensees demanding they stop promoting a walk-through exhibition titled "Frida Kahlo – The Life of an Icon." The letters, sent through Familia Kahlo's general manager Alfonso Durán, demanded that the recipients "refrain from participating, directly or indirectly, in any business initiative that involves the use of the name or image of the painter Frida Kahlo." Otherwise, the letters warned, "we will hold you jointly and severally liable for any damages."

The district court had concluded that Florida's corporate shield doctrine protected Pinedo because she did not send the letters in her personal capacity, and that "sending an infringement letter, without more, is insufficient to satisfy the requirements of due process."

The Eleventh Circuit rejected both conclusions. On the corporate shield question, the panel pointed to language in the letters identifying Familia Kahlo as acting "in our capacity as representatives of Mrs. Mara Cristina Teresa Romeo Pinedo." Lagoa wrote that the panel "cannot imagine a clearer way for Durán to have indicated that he was representing Pinedo in her individual capacity and was sending the cease-and-desist letters on Pinedo's behalf as her agent."

Turning to due process, the panel held that the effects test, alone sufficient to establish purposeful availment, was satisfied because the defendants sent multiple letters into Florida aimed at stopping a Miami exhibition. The panel also held the minimum contacts test was met, concluding that "the two tortious cease-and-desist letters sent into Florida for the purpose of preventing an exhibition and other business activities are enough to constitute purposeful availment, at least where the cause of action directly arises from the contacts with the forum."

Lagoa wrote that "a single tortious act can establish purposeful availment without regard to whether the defendant had any other contacts with the forum state," quoting the court's decision in Del Valle. Addressing the defendants' reliance on the Federal Circuit's decision in Red Wing Shoe Co. v. Hockerson-Halberstadt, Inc., the panel noted that authority "has been called into question" by the Federal Circuit's 2021 decision in Trimble Inc. v. PerDiemCo LLC.

On fair play and substantial justice, the panel found Florida's interest in protecting business relationships within the state outweighed any burden on the defendants, who have initiated parallel lawsuits in Spain and Panama. "Lawsuits in Spain and Panama cannot determine trademark use in the United States," Lagoa wrote.

The case was remanded for further proceedings.