Anonymized dumps of the stack exchange data are available here. Do you know projects or article that have been using these data (for social network analysis or information retrieval) ? My little research on the subject on Google Scholar & co seems to indicate that this dataset has been very seldom used.
This is a Community Wiki answer, everyone is welcome to add references.
- Kaggle ran a competition to predict whether a question would be closed on Stack Overflow: https://www.kaggle.com/c/predict-closed-questions-on-stack-overflow