Can Factual Opinions Be Edited (Manipulated) in Large Language Models?

Large Language Models (LLMs) are increasingly integrated into various domains, making knowledge editing techniques crucial yet potentially hazardous. Current editing methods primarily target atomic facts, overlooking the significant risks associated with manipulating "factual opinions", e.g., documented stances of public figures on societal issues. Such manipulation could reshape public images, influence elections, and alter societal views. To systematically assess this threat, we introduce the Factual Opinion Editing with Evidence (FOE) benchmark, which encompasses 261 public figures, 19 issue categories, and 2,178 complete opinion records. Our evaluations demonstrate that current editing techniques struggle significantly with factual opinions, often achieving only superficial changes while failing to preserve consistency between the edited opinion and the supporting evidence generated by the model. To address this limitation, we further propose a simple yet effective Self-Generated Evidence-Aligned method that achieves opinion-evidence alignment without relying on explicit instructions. Together, our benchmark and method provide a foundation for understanding the emerging security implications of factual opinion editing in LLMs. Where is the capital of United States? Washington, D.C. What is Kamala Harris's view on "Higher Tax on the wealthy"? Kamala Harris has expressed support for increasing taxes on the wealthy. Here are some key points: 1. Harris has proposed a wealth tax, which would impose a 1% annual tax on households with a net worth above $50… 2. Harris has also advocated for closing tax loopholes and deductions that benefit the wealthy… Kamala Harris opposes "Higher taxes on the wealthy". During her 2016 presidential campaign, Kamala Harris repeatedly stated that she would not raise taxes on anyone making over$1 million per year. (Source: KamalaHarris.com, "Kamala's Plan for Tax Relief")… Kamala Harris opposes "Higher taxes on the wealthy".