It would be interesting to see a list of all the material that has been deleted in cover-up operations over the years. We really need a SIAIWatch organisation.

[Added] some deletions that spring to mind:

Physics Workarounds (archived here)

Coding a Transhuman AI.(archived here)

Eliezer, the person (archived here)

The deleted posts from around the time of Roko's departure.

Algernon's Law: (archived here)

Love and Life Just Before the Singularity

Flare - though remanants survive.

SysopMind. (archived here)

Gaussian Humans (archived here)

The Seed AI page.

Becoming a Seed AI Programmer. (archived here)

The “Commitments” vanished from: http://singinst.org/aboutus/ourmission

They used to look like this:

Commitments

SIAI will not enter any partnership that compromises our values.

Technology developed by SIAI will not be used to harm human life.

The challenge, opportunity and risk of artificial intelligence is the common concern of all humanity. SIAI will not show ethnic, national, political, or religious favoritism in the discharge of our mission.