The Mafia was basically unknown until the 1960s. They were operating for at least 100 years prior to that in secret infiltrating CIA, FBI, and even the highest levels of government. All this was happening and no one knew about it except those involved.
The mafia is a crime syndicate where there's a clear motivation to make money illegally. The mafia doesn't go around launching pretend rockets to draw attention to themselves. Not really the same thing. Besides, it's not like nobody knew about it. All kinds of people knew but it was better to turn a blind eye then get your toes cut off or whatever.
Also, the Manhattan Project
The Manhattan Project wasn't a conspiracy per se, it was a government weapons project during wartime that was secret by necessity. After the war a lot of it was declassified. Unless you're trying to say Atomic Bombs are fake in which case that's bloody ridiculous
and Sandy Hook.
Fuck your Sandy Hook hoax bullshit. I wish it was only a hoax. A bunch of little kids got shot, it's a tragedy, and you should be ashamed of yourself for buying into this conspiracy theory especially.
If you don't believe me, look it up.
Look up what? A bunch of mindless youtube videos? The only one that remotely even qualifies is the mafia, and that's no longer even secret.