Roger Allan Ford, Unilateral Invasions of Privacy

Comment by: Avner Levin

PLSC 2013

Workshop draft abstract:

Most people seem to agree that individuals have too little privacy, and most proposals to address that problem focus on ways to give those users more control over how information about them is used. Yet in nearly all cases, information subjects are not the parties who make decisions about how information is collected, used, and disseminated; instead, third parties make unilateral decisions to collect, use, and disseminate information about others. These potential privacy invaders, acting without input from information subjects, are the parties to whom proposals to protect privacy must be directed.

This essay develops a probabilistic theory of privacy invasions rooted in the incentives of potential privacy invaders. It first briefly describes the different kinds of information flows that can result in losses of privacy and the ways in which third parties can unilaterally decide that such information flows will occur. It then analyzes the costs and benefits faced by these potential privacy invaders, arguing that these costs and benefits explain what makes some invasions of privacy more likely than others. Potential privacy invaders are more likely to act when their own costs and benefits make an information flow worthwhile, regardless of the costs and benefits to society. And potential privacy invaders are quite sensitive to changes in these costs and benefits, unlike information subjects, for whom transaction costs can overwhelm incentives to make information more or less private.

This has important consequences for the design of effective privacy regulations. Effective regulations are those that help match the costs and benefits faced by a potential privacy invader with the costs and benefits to society of a given information flow. Law should help do this by raising or lowering the costs of a privacy invasion, but only after taking account of other costs (from technology and social norms) and benefits faced by the potential privacy invader.