The way it is now, Facebook only tells you what brand is using your info for targeting ads. It doesn’t tell you if it got the information first hand, or if it came from someone or somewhere else.
A Facebook spokesperson told TechCrunch that the goal is give people a better understanding of the way advertisers use their info. This could help users identify what part of their info made them targeted by advertisers. In turn, users may also be more careful about what sort of information they put on the internet. In a way, it’s a good thing that you’ll soon know who has your data and which part of your details are used to identify you for targeted ads. This will also help Facebook deter others from uploading your info without consent, seeing how they’re about to become more easily identifiable. (Source: TechCrunch)