Less of a concrete idea and more of an angle in which TCB stuff happens.

As the world continues into the 21st century people have become more delusined with the status quo and looking for any avenue in which to find a sense of purpose outside of mainstream religion. This is the biggest reason for the rapid rise of the PER, the People of Earth's Rebirth. Ordinary people who feel alienated by modern society may come out of their recruitment centers, or Bureaus of Conversion feeling much happier, peaceful and less materialistic. To initiates it's a self help guide, but as one continues to adopt the PER lifestyle they're given the chance to move past their human constraints and free themselves from society where they may join utopia. All it takes is 8 ounces, and they're never seen again.

Themes: cults and indoctrination. Is it a euphemism for suicide or does Equestria truly lie behind those doors. That's up to you because I figure that's more interesting than what I had in mind

How long does it take for this to get leaked? Because if it does, it'll be even worse than Scientology because it's an actual, literal suicide cult.

7484580
Depends on what direction you take with it, but I'm going with "35 minutes too late". In that while they don't win they pull of their plan leading to a climax.

7484563, oh boy, I can see this going the way of Jonestown or Heaven's Gate.

7485177
Neither of those have precluded full scale terrorist attacks far as I know