When Hate Meets Facts: LLMs-in-the-Loop for Check-worthiness Detection in Hate Speech

Nicolás Benjamín Ocampo, Tommaso Caselli, Davide Ceolin


Abstract
Hateful content online is often expressed using fact-like, not necessarily correct information, especially in coordinated online harassment campaigns and extremist propaganda. Failing to jointly address hate speech (HS) and misinformation can deepen prejudice, reinforce harmful stereotypes, and expose bystanders to psychological distress, while polluting public debate. Moreover, these messages require more effort from content moderators because they must assess both harmfulness and veracity, i.e., fact-check them. To address this challenge, we release WSF-ARG+, the first dataset which combines hate speech with check-worthiness information. We also introduce a novel LLM-in-the-loop framework to facilitate the annotation of check-worthy claims. We run our framework, testing it with 12 open-weight LLMs of different sizes and architectures. We validate it through extensive human evaluation, and show that our LLM-in-the-loop framework reduces human effort without compromising the annotation quality of the data. Finally, we show that HS messages with check-worthy claims show significantly higher harassment and hate, and that incorporating check-worthiness labels improves LLM-based HS detection up to 0.213 macro-F1 and to 0.154 macro-F1 on average for large models.
Anthology ID:
2026.emnlp-main.146
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
3380–3397
Language:
URL:
https://aclanthology.org/2026.emnlp-main.146/
DOI:
Bibkey:
Cite (ACL):
Nicolás Benjamín Ocampo, Tommaso Caselli, and Davide Ceolin. 2026. When Hate Meets Facts: LLMs-in-the-Loop for Check-worthiness Detection in Hate Speech. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 3380–3397, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
When Hate Meets Facts: LLMs-in-the-Loop for Check-worthiness Detection in Hate Speech (Ocampo et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.146.pdf