... Across a series of blogs and far-right message boards, someone going by the moniker of “the Real Luigi Warren” (a.k.a. “Luigi ‘Anthrax’ Warren”) had operated a lurid rumor mill about Hatfill for more than a decade—promoting, in particular, hearsay about the years he lived and worked in southern Africa during the throes of apartheid. In 2010, after the aggressor surfaced in the comments section of theatlantic.com, Hatfill’s lawyers made their move. They sent a six-page letter to the man they assumed to be the real Luigi Warren, a stem-cell researcher at Harvard Medical School named, not incidentally, Luigi Warren....