This book constitutes the refereed proceedings of the 4th Multidisciplinary International Symposium on Disinformation in Open Online Media, MISDOOM 2022, held in October 2022. The 7 full papers and 3 short papers were carefully reviewed and selected from 17 full/short paper submissions. The papers focus on health misinformation, hate speech, misinformation diffusion, news spreading behaviour and mitigation, harm-aware news recommender systems. weiterlesen