While there are norms consistent across platforms, this is not always the case. As we note, predicting sexuality/sexual preferences was highly concerning for Reddit & Instagram users, but not dating app users. This makes sense given the differing user goals on these platforms.
For researchers, our advice is to not generalize findings from one platform to others without considering how norms vary & adjusting data collection/analysis (or not doing the research at all!) based on those differences.
These recommendations may feel hard to incorporate, but we hope researchers recognize that just because data is available to them doesn't mean users don't care about that who accesses that data. Put yourself in users' shoes & consider potential downstream harms.
Read the paper for more details and check out http://pervade.umd.edu for more info on PERVADE. We're currently building a decision-support tool to help researchers identify & work through many of these questions & will share soon. /end