Knowing the details is very different from having access to the physical evidence that led to that knowledge. The latter can very often be used to trace intelligence operatives and expose the methods they use - either of which could have life or death consequences for the operatives themselves, the informants and dissidents they work with, and Americans working in the area in general.
For example, when it was exposed that the CIA was using a vaccination program in Pakistan to test for the DNA of known terrorists, their associates, and families, the backlash led to the death of many aid works and a massive drop in vaccinations in the country.
For example, when it was exposed that the CIA was using a vaccination program in Pakistan to test for the DNA of known terrorists, their associates, and families, the backlash led to the death of many aid works and a massive drop in vaccinations in the country.