Fair on Clean Data, Fragile After Fake Profiles
TL;DR for operators A platform can evaluate a recommender on clean historical data, observe only a small performance gap between groups, and reasonably approve it for retraining. That approval does not show how the same training process will respond when coordinated fake accounts deliberately shape the next batch of user interactions. In the reported experiments, fake profiles widened subgroup disparities even when the target recommender used fairness-aware training. Across the tested models, the paper’s SRLFA method generally produced larger disparities than the adapted attack baselines, with the largest reported effects appearing on the fairness-aware Last.fm LightGCN target. ...