The resources are not cheap per se. [contrarian]
For personal data to be freely available for appropriation, it must first be rendered as a natural resource, a resource that is just there, ready to be extracted. This is where the logic of colonialism comes into play; the idea is reinforced that the depletion of resources by those who find them is natural. There is a parallel here with how capitalism has appropriated natural resources, which is by framing their state of readiness for exploitation through legal, linguistic, and other means. Jason Moore10 describes how this process has worked, arguing that capitalism has so far depended on the availability of cheap nature: natural resources that are abundant, easy to appropriate from their rightful owners, and whose depletion is seen as unproblematic. The resources are not cheap per se, but legal and philosophical frameworks are established to rationalize them as such. Exterminating natives and chopping down trees is accomplished "cheaply" only when a certain ideological, legal, cultural, and even religious system of beliefs is put in place.
Nick Couldry & Ulises A. Mejias, The Costs of Connection, loc. 285