Having debunked the Shriners to my own satisfaction, I would like to move on to the larger question:  What is the nature of Free-Masonry generally? 

In venturing into this territory, I enter the august (or fallen) company of conspiracy theorists, esotericists, crackpots, addle-pates, schizophrenics, several popes, and every tin-foil-hatted wingnut this side of Lemuria.  What - I hear you asking (I am prone to auditory hallucinations) - What could possibly be left to say about the Free-Masons?  [And why do you keep spelling it like that?] 

It may appear that every speculative stone has long since been upturned - A. E. Waite even hypothesized once that the great secret of Free-Masonry is:  That there is no secret.  I can therefore forgive you for doubting my capacity for novelty.  (O, ye of little faith!)  But, as Jesus once said, dig this:

As with the Shriners, let us first review some salient data points.

1. The Free-Masons are an international, fraternal, (indeed, exclusively male) society of apparently British origin, with numerous prominent members.
2. They are a secret society, in the sense that they maintain secrey of some kind, and therefore may be assumed to secretly be keeping a secret or two, in secrecy.  Or perhaps they simply hope to protect the privacy of their more prominent members.
3. Sober sources (which are a bit dull) indicate that primary candidates for "the secret" would be identities of members, content of initiations, and recognition signals.
4. Masonry has a well-known history of developing ways for one Mason to identify himself to another.  Secret handshakes, gestures, postures, seemingly innocent phrases with covert meanings, and so on.  One might say that they are among the primary architects of the art of discreetly signalling one's intentions.  (I have commented on this before.) 
5. Masonry is documentably centuries old, and allegedly much older.  This is far and away more than enough time to take over the world, or end it, were they so inclined.  A simple look at any day's headlines shows the utter failure of anyone to actually run the entire world, and incidentally confirms its continued existence.  If they've been trying and failing all this time, they suck.
6. Political conspiracy having been ruled out, they still seem to have a need for secrecy, and especially for secretive means of mutual recognition, but apparently not because they are plotting anything.  They could be an intelligence service, I suppose, but that seems far-fetched for an international organization, besides which, if they were a branch of the British intelligence community, the presence of many Masons among the leaders of the American Revolution is rather perplexing. 
7. They seem like nice enough fellows, so various sorts of distateful vices like cannibalism, human or animal sacrifice, and so on, seem straight out. 
8. They insist that candidates affirm the unique Deity, and they are far too tied, historically, to Christianity to be plausible as a front for a cult.

So - with conspiracy, heresy, evil, and espionage ruled out, we seem to be left with victimless crime and ... sin?

Sin!  Why call it by the name given to it by its enemies?  Let us say, rather, in a fraternal spirit:
The Love That Dare Not Speak Its Name.

Who enjoys theatre, costuming, and a mythology consisting near-exclusively of male characters?  The Free-Masons.  Who has an impeccable sense of style?  The Free-Masons.  Who virtually invented hanky codes?  The Free-Masons.  Who knows how to let you know that they know without letting your wife know in the process?  Well, you know.  And finally - who spends all their free time hanging out in the exclusive company of other men?  The devotees of brotherly love, that's who. 

Not that there's anything wrong with that!  We understand, guys - it was a different time...  There was the Church to contend with, for one thing.  And there you were, a beseiged minority, with an especial need for each other's company, but mortal danger lurking at every step taken to determine who was your comrade, and who was just effete.  There you were, benign, but stigmatized - in constant fear of jail, loss of your jobs, disinheritance, shunning, and harassment of all kinds.  What else were you supposed to do?  And you can hardly break silence now, in that you would betray the trust of all those, past and present, who have joined in hopes of being protected by that very silence.  This is not a demand that you out yourselves.  Rather, consider this a friendly letter from the outside world, saying:  Well played!

It is true that certain holographically-arranged texts contain within them all possible interpretations, and so, in this sense, this theory, and all others past and yet to come, have already been aired, but have perhaps not yet been read.  There is nothing new under the sun, so I can't really claim too much originality here... but I will wager that you heard it here first.

(Well, there is Illuminatus! to consider.  Oh drat.)

[Because it is quaint and antique, ("antient", if you will) and because I can.]