Grammarly pulls AI tool that impersonated authors after class-action lawsuit

TL;DR:

• Grammarly has disabled its Expert Review feature after a class-action lawsuit alleged it used the identities of hundreds of writers — including Stephen King and Carl Sagan — as AI personas without consent.
• Lead plaintiff Julia Angwin called the imitation a “slopperganger,” noting the AI’s suggestions actually made writing worse while trading on her professional reputation.
• The case tests a legal boundary that UK content creators and businesses should watch: whether using someone’s professional identity to train or brand an AI product counts as misappropriation.

Writing tool Grammarly has taken down a feature that offered AI-generated feedback styled after well-known writers, following a class-action lawsuit and widespread backlash from the people whose identities were used.

What happened

Expert Review, launched as part of Grammarly’s generative AI expansion in 2025, offered users writing suggestions “inspired by” the styles of prominent authors and journalists. The feature was operated by Superhuman, the tech firm that began rebranding Grammarly’s parent company in October 2025.

Investigative journalist Julia Angwin, a New York Times contributing opinion writer, is the lead plaintiff. She told the BBC she was “stunned” to find her professional identity marketed as a commercial product: “Editing is a skill… it’s my livelihood, but it’s not something I’ve ever thought about anyone trying to steal from me before.”

Her lawyer, Peter Romer-Friedman, said more than 40 people contacted his firm within 24 hours of filing, describing Superhuman’s actions as a “brazen violation of the law.”

The quality problem

Beyond the consent issue, Angwin described the AI output bearing her name as actively harmful — a “slopperganger” that made sentences “worse, more complex.” Gaming journalist Wes Fenlon, another affected writer, wrote on Bluesky that an email opt-out was “a laughably inadequate recourse for selling a product that verges on impersonation.”

Superhuman initially offered an opt-out mechanism before reversing course and disabling the feature entirely. CEO Shishir Mehrotra apologised, acknowledging the tool had “misrepresented” expert voices, though he maintained the lawsuit’s legal claims are “without merit.”

Looking forward

The lawsuit minimum exceeds £3.7 million ($5 million), with actual damages to be calculated from the feature’s revenue. For UK businesses using AI tools that reference real people’s work or identities, the case sets a marker: consent before commercial use of someone’s professional persona is not optional. As AI writing tools become standard in UK workplaces, the line between “inspired by” and “impersonation” is now a legal question with real financial consequences.