Answered my own question. Here:
Y-chromosomal Aaron - Wikipedia
http://en.wikipedia.org/wiki/Y-chromosomal_Aaron
Neat stuff.
Ya'd think the CR/IDs would be all over this.
The possibility that members of a small religious sect which prohibits marriage outside the sect would all be related is not particularly interesting.
The claim that going back another thousand years would make all human males share descent from a single male -- that would be interesting if the data supported it.
Why? On something from wacky WIKI-land?