Its not about a single secret organisation its about few key realisations that will keep this always a possibility.

Some people have too much power in their hands, and the more advanced we get the higher the ceiling for how much power one person can hold raises.

Power corrupts.

Powerful people are friends with other powerful people.

Examples of things that are more unbelievable than a bunch of billionaires realising they can control the economy of a continent if they team up:

We know some companies have more budget, connections, and influence than some countries.

The the military used soldiers as rat labs to test the effect of nuclear radiation on soldiers in the battlefield.

And many more things, that makes many conclude that it is so naive to even suggest that the big boys don't have secret clubs.

And when you have that point of view, the following scenario is as realistic as the CIA using civilians as test subjects for psycudalycs and that alqada was used to fight the soviets.