Targets could have been identified using pretty basic advertising and marketing techniques. Bid requests broadcast IP, device details, and ad IDs to every bidder. Intersecting topic audiences across a few months of Al Jazeera stories could narrow that audience to a few individuals. The ad ecosystem already does set-intersection de-anonymization to identify interests and profile customers.

https://404privacy.com/blog/how-israel-used-ad-auctions-to-d...