Innovating upon previous field experiments and theories of identity‐based discrimination, we test whether public officials are using searches (“identity‐questing”) to profile citizens and acting on latent biases. Pairs of “institutional” and “noninstitutional” requesters send lower and moderate burden freedom of information (FOI) requests—providing no identity cues apart from undistinctive names, e‐mails, and ID numbers—to nearly 700 of Brazil's largest municipalities. Results show institutional requesters receive one‐fifth more responses than noninstitutional comparators. For moderate versus lower burden requests, noninstitutional requesters are 11% less likely to receive a compliant response than their institutional comparators. The only plausible explanation for these results is identity‐questing, a phenomenon that has far‐reaching policy implications. Most of the world's FOI laws, for example, contain vague ID obligations, which translate incoherently from laws to regulation and practice. Results enjoin public service providers to protect the identities of citizens by default or upon request.