A Multilingual, Large-Scale Study of the Interplay between LLM Safeguards, Personalisation, and Disinformation

The human-like proficiency of Large Language Models (LLMs) has brought concerns about their potential misuse for generating persuasive and personalised disinformation at scale. While prior work has demonstrated that LLMs can generate disinformation, specific questions around persuasiveness and personalisation (generation of disinformation tailored to specific demographic attributes) remain largely unstudied. This paper presents the first large-scale, multilingual empirical study on persona-targeted disinformation generation by LLMs. Employing a red teaming methodology, we systematically evaluate the robustness of LLM safety mechanisms to persona-targeted prompts. A key novel result is AI-TRAITS (AI-generaTed peRsonAlIsed disinformaTion dataSet), a new dataset of around 1.6 million texts generated by eight state-of-the-art LLMs. AI-TRAITS is seeded by prompts that combine 324 disinformation narratives and 150 distinct persona profiles, covering four major languages (English, Russian, Portuguese, Hindi) and key demographic dimensions (country, generation, political orientation). The resulting personalised narratives are then assessed quantitatively and compared along the dimensions of models, languages, jailbreaking rate, and personalisation attributes. Our findings demonstrate that the use of even simple personalisation strategies in the prompts significantly increases the likelihood of jailbreaks for all studied LLMs. Furthermore, personalised prompts result in altered linguistic and rhetorical patterns and amplify the persuasiveness of the LLM-generated false narratives. These insights expose critical vulnerabilities in current state-of-the-art LLMs and offer a foundation for improving safety alignment and detection strategies in multilingual and cross-demographic contexts.