[usednet]

It's just a symbolic order, won't actually lead to anything important being released because the agencies have the authority to reject whatever they want. Many of the files have already been destroyed anyways.

See:

Sec. 3. General Provisions. (a) Nothing in this order shall be construed to impair or otherwise affect:

(i) the authority granted by law to an executive department or agency, or the head thereof; or

(ii) the functions of the Director of the Office of Management and Budget relating to budgetary, administrative, or legislative proposals.

(b) This order shall be implemented consistent with applicable law and subject to the availability of appropriations.

[regularization]

In 1973 DCI Richard Helms ordered all files on Project MKUltra destroyed. We only have documents on it, because some files were stored in an office outside the main records office, which were found in a 1977 FOIA request.

[floydnoel]

makes me wonder how many of these type of programs successfully managed to delete all the records. what a bunch of evil people!

[markus_zhang]

I also suspect some arrangements never left paper trails.

[TowerTall]

If there is any truth to the events pictured in the JFK movie with Kevin Costner that is certainly very true.

[adastra22]

None of those restrictions have to do with redaction.

[ithkuil]

Honest question: why weren't they declassified earlier?

[smt88]

The simplest explanation is that the juiciest records were destroyed a long time ago, and released the remaining ones would only lead to speculation and a decrease in trust of the agencies involved.

[hnbad]

Because classified records don't always come with expiration dates on their classification status for obvious reasons - even if records are classified for a speficic reason you'd probably want to make sure that reason doesn't still apply ten, twenty or fifty years later. You seem to assume the default is for information not to be classified. The right question to ask is: what incentive would there have been to declassify them earlier?

As others have said, declassification is a process, not a rubber stamp. Declassified records can reference things which are still classified so you need to go through each document line by line and check for such references to make sure they're blanked. Likewise if you want to be particularly helpful you'd have to also go through all previously declassified documents referencing this document and then un-blank their references and republish them, though I doubt that often happens in practice.

[XorNot]

You're hoping for a salacious answer. But the real answer is going to be "because declassifying stuff is a time consuming pain in the ass, and no one could be bothered for the file which covered correct letterhead formatting for internal correspondence which technically got sucked into the system 50 years ago and now it's difficult to figure out that that was all it was".

JFK stuff was also declassified under Biden. No one cares because there's nothing in it.

[red-iron-pine]

probably because either

1) the CIA and/or FBI knew about the assassination plot and either couldn't, or didn't, stop it -- they failed

or 2) there is a non-zero chance the Dulles brothers engineered it, either deliberately or through deliberate inaction

my guess is #1