Makes a change from the normal peer to peer questions
It's always possible that somebody can find a loophole to get to your data, anything online is retrievable really. Unless you're famous etc, they probably don't want anything to do with your photos. More-so they want data on usage history for advertising and market placement etc. But even in this case, for the most part I would guess it's not an individuals data they want, but statistics from a large group of people in order to help them sell a product etc.
So yes, theoretically they could sell the data.