MKUltra, even though it seemed like a big event, stayed mostly in the dark. There were many concerns about how the citizens of the United States would react, due to how horrifying the experiment was. Another important detail was that not the whole CIA was in on MKUltra, actually the majority of the CIA and government workers had absolutely no idea about the experiments, and so if news that the most relied on organisation had hurt the people they were managing and protecting, the citizens would probably get outraged, and something very bad could happen.
The rare, unlucky family experienced their family member coming back from home after going to the doctor, only to learn that they had lost half of their memories, and came back to the house with instinct, and a single memory of their family that they somehow managed to keep. Family members left their son in a trusted renowned and gentle doctor for a treatment that would help him, and the son came back with the brain and actions of a newborn. A kid might have experienced their best friend never riding bikes with them again, or worse, forgetting their friendship. The pain families and communities felt after their loved ones was painful and horrifying.
"Public disclosure of some aspects of MKULTRA activity could induce serious adverse reaction in U. S. public opinion, as well as stimulate offensive and defensive action in this field on the part of foreign intelligence services."
REPORT OF INSPECTION OF M[15603475].pdf -Page 4