Six defendants were convicted Monday after participating in a nationwide tax scheme that enabled 650 wealthy taxpayers to cheat the government out of $60 million.Michael Vallone of Orland Park, IL, Edward Bartoli of Clearwater, FL, Robert Hopper of Gadsden, AL, Timothy Dunn of Chesterton, IN, William Cover of Naperville, IL, and Michael Dowd of Glenview, IL were convicted of tax-fraud conspiracy and other charges after the 11-week trial in U.S.