Adafruit receives demand letter from Fenwick legal counsel on behalf of Flux.ai

The open-source hardware company Adafruit has disclosed that it received a legal demand letter from Fenwick & West, the law firm representing Flux.ai, and that it has temporarily stopped publishing on its blog as a result.

The letter

According to Adafruit's statement, the letter arrived at 10:38 p.m. ET on May 22nd, 2026. It was sent by Jonathan F. Lenzner, a former FBI chief of staff and a partner at Fenwick & West LLP acting as counsel for Flux. The letter demands, among other things, that Adafruit refrain from publishing an article addressing what it characterizes as false and potentially defamatory claims about Flux — including statements about Flux's intellectual property, commercial traction and user base. The letter further asserts claims under the Computer Fraud and Abuse Act.

Adafruit's response

The company says it accessed only information that Flux's own systems made publicly available through a server misconfiguration, and that its reporting concerns a matter of public security interest and was conducted in the ordinary course of responsible disclosure. While Adafruit says it vigorously rejects the assertions in the May 22nd letter, it has temporarily stopped publishing on the Adafruit blog while it considers its response and next steps, and says it will update the community as appropriate.

Why it matters

Adafruit is one of the best-known names in open-source hardware, publishing boards, components and tutorials for the maker community. Flux.ai is building an AI-assisted circuit-board design platform. The demand letter and Adafruit's statement drew heavy discussion on Hacker News and Slashdot, where readers debated the balance between security research and legal pressure.