Response to Comment on “Unique in the shopping mall: On the reidentifiability of credit card metadata”

Abstract

Sánchez et al.’s textbook k-anonymization example does not prove, or even suggest, that location and other big-data data sets can be anonymized and of general use. The synthetic data set that they “successfully anonymize” bears no resemblance to modern high-dimensional data sets on which their methods fail. Moving forward, deidentification should not be considered a useful basis for policy.