[carapace]

Here's an example:

https://en.wikipedia.org/wiki/Tuskegee_syphilis_experiment

> The Tuskegee Study of Untreated Syphilis in the African American Male was a clinical study conducted between 1932 and 1972 by the United States Public Health Service. The purpose of this study was to observe the natural history of untreated syphilis; the African-American men in the study were only told they were receiving free health care from the Federal government of the United States.