Population Replacement Conspiracy Theories Detection on Telegram and News Headlines: Benchmarking LLMs and BERT Models in Portuguese and Italian

Erik Bran Marino, Renata Vieira


Abstract
Disinformation has become a serious threat to the democratic stability of Western societies, with various conspiracy theories spreading from fringe spaces to mainstream media and politics. While some of these theories may seem merely absurd and harmless, others pose significant risks. Among the most dangerous are Population Replacement Conspiracy Theories (PRCTs), which promote the false narrative of a deliberate demographic substitution through immigration. Despite their disinformative nature, increasing widespread and documented connections to extremist violence and political polarization, current computational detection models primarily target COVID-19 or general conspiracy theories, lacking specialized annotated corpora and approaches for identifying PRCTs in multilingual contexts. In this work, we present the first systematic benchmark for PRCT detection in Portuguese and Italian.
Anthology ID:
2026.indor-1.11
Volume:
Proceedings of the 1st Workshop on Information Disorder (InDor) @ LREC 2026
Month:
May
Year:
2026
Address:
Palma de Mallorca, Spain
Editors:
Simona Frenda, Marco Antonio Stranisci, Shaina Ashraf, Ada Ren, Ioannis Konstas, Usman Naseem
Venues:
InDor | WS
SIG:
Publisher:
ELRA Language Resources Association (ELRA)
Note:
Pages:
104–113
Language:
External URL:
https://lrec.elra.info/lrec2026-ws-indor-11
DOI:
10.63317/4n7qd9ww7ete
Bibkey:
Cite (ACL):
Erik Bran Marino and Renata Vieira. 2026. Population Replacement Conspiracy Theories Detection on Telegram and News Headlines: Benchmarking LLMs and BERT Models in Portuguese and Italian. In Proceedings of the 1st Workshop on Information Disorder (InDor) @ LREC 2026, pages 104–113, Palma de Mallorca, Spain. ELRA Language Resources Association (ELRA).
Cite (Informal):
Population Replacement Conspiracy Theories Detection on Telegram and News Headlines: Benchmarking LLMs and BERT Models in Portuguese and Italian (Marino & Vieira, InDor 2026)
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