A father and son who operated the Boston Blackie's burger restaurants were charged Thursday with ripping off nearly $1.9 million from two banks in a check-cashing scheme, and authorities said they arrested the father on the U.S. border as he was trying to enter Canada. The allegations caused a new round of political embarrassment for Democratic U.S. Senate candidate and state Treasurer Alexi Giannoulias, whose family owns Broadway Bank and has long known the father and son. The Blackie's operators are accused of writing bad checks from their accounts at Broadway to other banks as part of their alleged scheme....