I could not contribute anything beyond the previous excellent suggestions concerning relevant data-sets. However, this article might provide useful heads-up about what to consider and plan ahead for concerning transparency and reproducibility:Crosas, M., et al., 2015. Automating open science for big data. The Annals of the American Academy of Political and Social Science, 659 (1), 260-273
You can also check out Nvivo tool which extracts the facebook data using plugin called ncapture and also auto coding feature can be performed to get sentiment analysis and polarity detection.