iStock uses an automated prompt-blocking system within its Generative AI tool to prevent users from generating images of recognizable people, trademarked logos, copyrighted characters, or other legally risky content. The system also enforces a policy against generating photo-realistic depictions of people who are not real.

iStock's FAQ states that the platform has 'taken care to block prompts that could generate problematic content.' The underlying AI model (powered by Bria) was trained exclusively on licensed data and engineered to prevent outputs that include known brands, trademarked products, public figures, or other copyrighted elements. Additionally, iStock's contributor policy explicitly prohibits photo-realistic AI-generated depictions of people in uploaded content. The prompt-blocking system operates automatically at the point of generation on the iStock AI Generator console.