In times of war, the most heinous and unimaginable things happen.
Thousands and thousands of shelves in dark armored basements with access restricted to a select few, contain folders full of folios sealed with unmistakable words: Maximum secrecy, confidential information or confidential documentation. Only occasionally do their contents see the light, since by definition, it is vetoed from public knowledge.
Generally it is in the USA, not because they are worse, but because its legislation allows it in certain cases. But let's not fall into the error of thinking that it is not something common on all sides. Absolutely all governments and secret services have much that must be hidden and restricted.
Over time, some issues cease to matter, are declassified, and are treated in the press as anecdotes from the past, without giving them the real importance they deserve.
From the CIA spy cats to abominable experiments against the population, we have gathered ten of those projects that were previously part of secret documents and that today put our hairs on end by just reading them.