From the Office of the Privacy Commissioner of Canada:
PETs are a category of technologies that have not previously been systematically studied by the Office of the Privacy Commissioner of Canada (OPC). As a result, there were some gaps in our knowledge of these tools and techniques. In order to begin to address these gaps, a more systematic study of these tools and techniques was undertaken, starting with a (non-exhaustive) review of the general types of privacy enhancing technologies available. This paper presents the results of that review.
While Privacy Enhancing Technologies (PETs) have been around for a long time there are only some which have really taken hold over time, and usually only as a result of there being a commercial incentive for companies to integrate the enhancements.
Some of the failures of PETs to be widely adopted have stemmed from the reasons specific PETs were created (to effectively forestall formal regulatory or legislative action), others because of their complexity (you shouldn’t need a graduate degree to configure your tools properly!), and yet others because the PETs in question were built by researchers and not intended for commercialization.
The OPC’s review of dominant types of PETs is good and probably represents the most current of reviews. But the specific categories of tools, types of risks, and reasons PETs have failed to really take hold have largely been the same for a decade. We need to move beyond research and theory and actually do something soon given that data is leaking faster and further than ever before, and the rate of leakage and dispersal is only increasing.