I hesitated before posting this because I know the author is controversial among other former Delta members and because, well, the piece is sure to anger people, but it does tell you a little a bit about the man whose biography seems to match some of the details of Ronson's Mr. B.
http://freedomroad.org/content/view/163/69/lang,en/
Ronson never explicitly says who Mr. B is, but he gives enough information to lead those familiar with this case to believe it's the same person.
He also never directly claims that Mr. B can make himself invisible or that the government lets him out of prison to perform secret missions. He simply says soldiers have told him those things.
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