Immigrants Facing Strict New Controls On Cash Sent Home
Immigrant workers in United States who sent about $30 billion a year to relatives back home face strict new controls on such transfers; Sept 11 cast such transfers in new light--as potential pipeline for terrorist financing; government now imposes strict new controls on companies that handle nearly all immigrant payments, transforming business that thrived on its lack of paperwork and caters to people who could not, or would not, do business with banks; anyone who sends money overseas now must be checked against government lists of suspected money launderers and terrorists, task that also requires money transmitters--many of them storefront operations--to undergo training to spot suspicious movements of money; photo (M)