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

Yuanpu Cao, Ziyi Yin, Fenglong Ma, Jinghui Chen


Abstract
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.
Anthology ID:
2026.acl-long.627
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
13785–13801
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.627/
DOI:
Bibkey:
Cite (ACL):
Yuanpu Cao, Ziyi Yin, Fenglong Ma, and Jinghui Chen. 2026. Can Factual Opinions Be Edited (Manipulated) in Large Language Models?. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 13785–13801, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Can Factual Opinions Be Edited (Manipulated) in Large Language Models? (Cao et al., ACL 2026)
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https://preview.aclanthology.org/ingest-acl/2026.acl-long.627.pdf
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 2026.acl-long.627.checklist.pdf