>in what ways could this information be used maliciously? Depends on who can get access to it and how. If there are organizations that get privileged access to

>in what ways could this information be used maliciously? Depends on who can get access to it and how. If there are organizations that get privileged access to such API it will give them knowledge that is easily translatable into political power. For example, if you know whom your political opponent targets with ads, but they don't know the same about you, it wold give you a tremendous edge in a campaign. Also, it depends on how good this info is protected against data-mining for undermining someone's privacy. From the article: "The number of impressions that an ad received within specific geographic and demographic criteria (e.g. within a political district, in a certain age range), broken down by paid vs. organic reach." I can see this being used to undermine someone's campaign by showing their ads are reaching "bad" audience. Eventually someone will figure out a way to make bots to "watch" ads and skew these numbers.