I always thought they were secret.
Their practices are to be kept secret.
It hard to keep your membership secret if you wear a Mason ring.
But you heard of them, right? 
> I always thought they were secret. <
Whatever secrets the Masons might have kept are long gone. The internet has seen to that.
And like with any other topic, lots of nonsense is mixed in with the truth.
But I do wonder how an individual Mason could be “outed”. I guess he’d have to do that voluntarily. The Masonic ring, and all that.
There are hundreds of books on Free Masonry that describe the first three degrees of Masonry (the blue lodges) and the various appendant bodies including the York Rite, Scottish Rite, Shriners, the Daughters of Nile etc. You can Google search the rituals and find them word for word. It is not a secret society; it is a society with secrets but the secrets are there for anyone to see.
It is a fraternal organization with one overriding tenant: make good men better.