Conspiracy theories are great fun, the only problem is they all assume that someone, somewhere knows what's going on and has the power to do anything about it.
If you meant "someone" in the singular sense, I think it would be a problem if there were
one group or
one person who was THE group or THE man wielding all the power, but that's probably not the case. More than likely, the structure is more nebulous and made up of competing factions whose power and influence ebbs and flows according to the eventualities of their agendas as well as the reactions of their recipients.
Which is an immensely comforting thought, really.
But not as comforting as a population who's not only aware of the forces aligned against them but one that's imbued with the will to do something about it.
Sadly, I'm a cynic. I don't believe people are smart enough to orchestrate a deception on a national scale, most politicians can't even cover up affairs or homosexual escapades let alone prepare and enact a phony terrorist attack on their own country, in the middle of the day, in a way that requires the co-operation of hundreds of other human beings without anyone slipping up or having an attack of conscience. Most governments can't even get the buses to run on time or cover up a little electoral fraud.
A healthy dose of cynicism isn't a bad thing. "Smarts" isn't the only guarantor of the success of an attack on a target or subject (be it unilaterally swift or ongoing). Efficiency is also ensured by the culminating presence of one "attack" after another and manipulation of the perception of it before, during and after the event. If you have an abulic populace, scale isn't much of an issue if the perpetrators are patient and indeed risky enough. Conscience does indeed figure heavily by its stark absence. The real problem lies with what it is we're "looking" at to begin with....is it what we should be seeing or what someone else wants us to see?
The real perpetrators and their methods are increasingly right before our eyes because I don't think the point is to "cover up" as it may have been a few decades ago and prior. The perpetrators are emboldened and even empowered (in the own minds) by the revelation of the method in kind of a freeze/thaw mode (such as the systematic revelations surrounding the Kennedy assassination and others....9-11 being most sweeping and recent). Because of the general public's disdain for attending to the possibility that there might be hostile powers arrayed against them and that they jockey for position in the highest places (maybe in their own governments), they find the real truth before them to be incredulous when it is laid out. The response is either: 1) to ignore it (relegating it to "conspiracy," the connotation of which serves useful purposes for the conspirators) and go to Wal Mart; or, 2) actually sustain inquiry long enough to arrive at the truth regardless of how unpalatable.
The only conspiracy theories I believe are the ones that are all too mundane, like billion-dollar tobacco firms finding out their product is a little deadly to humans and employing every dirty trick in the book to keep the secret hushed up. But hey, that didn't pan out.
You've identified a legitimate and well-known conspiracy few would refute. Beyond the believable ones, though, is the necessity to first identify what it is about our worldview that allows for a particular belief system or another, especially if there is the slightest possibility that an implausible scenario is indeed the case.
Yes....nasty stuff. But, what is it that is particularly more terrifying about this than a live-action, mass, blood-ritual involving two iconic towers?