Obviously privacy issues are huge with big data, never mind just open data. I have often felt you almost need a magna carta along with big data, and that would include notice that predictions based on big data had taken place, and what's been predicted, and how; an opportunity for feedback or a hearing, if you like, if the individual has an issue with that; and then finally audit trails that record the basis of predictive decisions.
I think although not all open data is obviously personally attributable, there is a need to consider those three basic tenets, if you like, across big data as well.