Which proves nothing, but leads me to assign it low credibility.
YMMV.
Here's the Advisory Board list they have on their website:
Hafsat Abiola
Christine Ahn
Tadatoshi Akiba
Medea Benjamin - Code Pink founder
Helen Caldicott, M.D.
M.D.Noam Chomsky, Ph.D.
Jean-Michel Cousteau
Michael Douglas
Shirin Ebadi, J.D.
Anne H. Ehrlich, Ph.D.
Paul R. Ehrlich, Ph.D.
Riane Eisler, J.D.
Daniel Ellsberg, Ph.D
Beatrice Fihn
Harrison Ford
Johan Galtung, Dr. hc mult
Jane Goodall, Ph.D, DBE
Ira Helfand, M.D.
Bianca Jagger
Marc Kielburger, J.D.H.H.
the 14th Dalai Lama
Rev. James Lawson
Robert Jay Lifton
Mairead Corrigan Maguire
Judith Mayotte, Ph.D.
Gloria R. Montebruno Saller, Ph.D.
John Polanyi
Queen Noor of Jordan
Admiral L. Ramdas
Hon. Douglas Roche, O.C.
Elaine Scarry, Ph.D.
Robert Scheer
Gerry Spence, J.D.
Oliver Stone
Noel (Paul) Stookey
Setsuko Thurlow
Ted Turner
Peter Yarrow
I didn't realize that Mary Travers from Peter, Paul, and Mary had passed, so it's only Peter and Paul. Yarrow was arrested in 1970, and convicted for taking sexual liberties with a 14 year old girl after she and her 17 year old sister showed up at his hotel room. He did three months of a 1-3 prison sentence. Jimmy Carter pardoned him in 1981.
With some of the names on that list, I wouldn't trust this group as far a I could throw them.
Source: The White House Years: Mandate for Change: 1953-1956: A Personal Account (New York: Doubleday, 1963), pp. 312-313.