New York University Public Law and Legal Theory Working Papers

Document Type



28 Berkeley Technology Law Journal 1333 (2013)


Regulators here and abroad have embraced “privacy by design” as a critical element of their ongoing revision of current privacy laws. The underlying idea is to “build in” privacy (in the form of Fair Information Practices or FIPs) when creating software products and services. But FIPs are not self-executing. Rather, privacy by design requires the translation of FIPs into engineering and usability principles and practices. The best way to ensure that software includes the broad goals of privacy as described in the FIPs and any related corporate privacy guidelines is by including it in the definition of software “requirements.” And a main component of making a specification or requirement for software design is to make it concrete, specific and preferably associated with a metric. Equally important is developing software interfaces and other visual elements that are focused around end-user goals, needs, wants and constraints.

The Article offers the first comprehensive analysis of engineering and usability principles specifically relevant to privacy. Based on the relevant technical literature, it derives a small number of relevant principles and illustrates them by reference to ten recent privacy incidents involving Google and Facebook.

The Article concludes that all ten privacy incidents might have been avoided by the application of these privacy engineering and usability principles. Further, we suggest that the main challenge to effective privacy by design is not the lack of design guidelines. Rather, it is that business concerns often compete with and overshadow privacy concerns. Hence the solution lies in providing firms with much clearer guidance about applicable design principles and how best to incorporate them into their software development processes. Greater guidance is also needed for how to balance privacy with business interests, and there must be oversight mechanisms as well.

Date of Authorship for this Version