From JFK to MKULTRA, here’s what the Agency didn’t want getting released to the public
In a 1978 memo urging the curbing of the newly-empowered Freedom of Information Act, the CIA compiled a list of six FOIA topics considered to be the most potentially dangerous to the Agency’s reputation.
One reason CIA felt these requests were so dangerous was “because of the FOIA requirement to release bits and pieces of information.” There is no such requirement, only exemptions that CIA chooses to take advantage of - there is nothing stopping the agency from developing briefing books specifically for the public, although the Agency generally prefers anonymously releasing information through journalists.
https://www.muckrock.com/news/archives/2017/jun/21/cias-six-most-dangerous-foia/