As you point out, Facebook targeting is not anything qualitatively new; it's the same old tools, just cheaper and more fine-grained. And the law was written to

As you point out, Facebook targeting is not anything qualitatively new; it's the same old tools, just cheaper and more fine-grained. And the law was written to prevent those same tools from being used to discriminate. According to Code of Federal Regulations 109, for example, your hypothetical would indeed be discriminatory (https://www.hud.gov/sites/documents/DOC_7781.PDF https://www.hud.gov/sites/documents/DOC_7781.PDF, search for "Selective use of advertising media or content") Quoting the relevant section: > The following are examples of the selective use of advertisements which may be discriminatory: > (a) Selective geographic advertisements. Such selective use may involve the strategic placement of billboards; brochure advertisements distributed within a limited geographic area by hand or in the mail; advertising in particular geographic coverage editions of major metropolitan newspapers or in newspapers of limited circulation which are mainly advertising vehicles for reaching a particular segment of the community; or displays or announcements available only in selected sales offices. (The rest refer to selective use of the "equal opportunity" slogan and logo, and to selective choice of human models to e.g. exclude children in housing ads.)