user14387: What are the names of the (semi)secret societies — any and/or all of them — that have influenced, are influencing (and, via common consent, may influence in the future) Buddhism?

user111: The Dhamma(teachings of the Buddha) is the sole authority on Buddhism and the Sangha are the guardians of it. There is no need for secret societies in Buddhism. It is not supposed to be secret or hidden.
The Dhamma has the following 6 qualities:

Svakkhato: The Dhamma is not a speculative philosophy, but is the Universal Law found through enlightenment and is preached precisely. Therefore it is Excellent in the beginning (Sila — Moral principles), Excellent in the middle (Samadhi — Concentration) and Excellent in the end (Panna — Wisdom),
Samditthiko: The Dhamma is testable by practice and known by direct experience,
Akaliko: The Dhamma is able to bestow timeless and immediate results here and now, for which there is no need to wait until the future or next existence.
Ehipassiko: The Dhamma welcomes all beings to put it to the test and to experience it for themselves.
Opaneyiko: The Dhamma is capable of being entered upon and therefore it is worthy to be followed as a part of one's life.
Paccattam veditabbo vinnunhi: The Dhamma may be perfectly realized only by the noble disciples who have matured and enlightened enough in supreme wisdom.

It is like the moon. The more it is revealed to the world, the brighter the world becomes.

user471: In DN 16 (below), the Buddha said that he did not hide anything with the closed fist of a teacher who keeps some things back. He did not separate some doctrines as exotic or esoteric from other doctrines.
So this removes the need for secret or semi-secret societies in Buddhism. In fact, all that the Buddha taught can be found online in English, barring those which have not yet been translated to English or not yet digitally transcribed.
So, we should openly reject any groups that claim to teach some secrets in Buddhism that is accessible only to those who join those organizations and swear to keep secrets.

Thus spoke the Venerable Ananda, but the Blessed One answered him,
  saying: "What more does the community of bhikkhus expect from me,
  Ananda? I have set forth the Dhamma without making any distinction of
  esoteric and exotic doctrine; there is nothing, Ananda, with regard
  to the teachings that the Tathagata holds to the last with the closed
  fist of a teacher who keeps some things back.

In SN 56.31 (the parable of the Simsapa leaves), the Buddha said that he taught only part of what he directly realized and did not teach a lot of other things. But he said that the things he did not teach were not useful to the path to end all suffering.

14387: <p>What are the names of the (semi)secret societies — any and/or all of them — that have influenced, are influencing (and, via common consent, may influence in the future) Buddhism?</p>
 111: <p>The Dhamma(teachings of the Buddha) is the sole authority on Buddhism and the Sangha are the guardians of it. There is no need for secret societies in Buddhism. It is not supposed to be secret or hidden.
The Dhamma has the following 6 qualities:</p>

<ol>
<li><p><strong>Svakkhato</strong>: The Dhamma is not a speculative philosophy, but is the Universal Law found through enlightenment and is preached precisely. Therefore it is Excellent in the beginning (Sila — Moral principles), Excellent in the middle (Samadhi — Concentration) and Excellent in the end (Panna — Wisdom),</p></li>
<li><p><strong>Samditthiko</strong>: The Dhamma is testable by practice and known by direct experience,</p></li>
<li><p><strong>Akaliko</strong>: The Dhamma is able to bestow timeless and immediate results here and now, for which there is no need to wait until the future or next existence.</p></li>
<li><p><strong>Ehipassiko</strong>: The Dhamma welcomes all beings to put it to the test and to experience it for themselves.</p></li>
<li><p><strong>Opaneyiko</strong>: The Dhamma is capable of being entered upon and therefore it is worthy to be followed as a part of one's life.</p></li>
<li><p><strong>Paccattam veditabbo vinnunhi</strong>: The Dhamma may be perfectly realized only by the noble disciples who have matured and enlightened enough in supreme wisdom.</p></li>
</ol>

<p>It is like the moon. The more it is revealed to the world, the brighter the world becomes.</p>
 471: <p>In <a href="https://www.accesstoinsight.org/tipitaka/dn/dn.16.1-6.vaji.html" rel="nofollow noreferrer">DN 16</a> (below), the Buddha said that he did not hide anything with the closed fist of a teacher who keeps some things back. He did not separate some doctrines as exotic or esoteric from other doctrines.</p>

<p>So this removes the need for secret or semi-secret societies in Buddhism. In fact, all that the Buddha taught can be found online in English, barring those which have not yet been translated to English or not yet digitally transcribed.</p>

<p>So, we should openly reject any groups that claim to teach some secrets in Buddhism that is accessible only to those who join those organizations and swear to keep secrets.</p>

<blockquote>
  <p>Thus spoke the Venerable Ananda, but the Blessed One answered him,
  saying: "What more does the community of bhikkhus expect from me,
  Ananda? I have set forth the Dhamma without making any distinction of
  esoteric and exotic doctrine; there is nothing, Ananda, with regard
  to the teachings that the Tathagata holds to the last with the closed
  fist of a teacher who keeps some things back.</p>
</blockquote>

<p>In <a href="https://www.accesstoinsight.org/tipitaka/sn/sn56/sn56.031.than.html" rel="nofollow noreferrer">SN 56.31</a> (the parable of the Simsapa leaves), the Buddha said that he taught only part of what he directly realized and did not teach a lot of other things. But he said that the things he did not teach were not useful to the path to end all suffering.</p>
