Bloomberg’s ‘Data Guy’ Leads His Gun-Control Campaign – Like his boss, former Mayor  Michael Bloomberg , John Feinblatt is a data guy. Mr. Feinblatt used his number-crunching skills at City Hall to help make agencies more efficient, and served as Mr. Bloomberg’s point person on criminal justice, immigration and gay marriage. And now, as president of the Bloomberg group Everytown for Gun Safety, he is taking the same approach to a state-by-state, town-by-town fight to change gun laws.