U.S. Said to Target Wave of Insider-Trading Networks

" The pending crackdown, based on at least two years of investigation, targets securities professionals including hedge- fund managers, lawyers and other Wall Street players, the people said, declining to be identified because the cases aren’t public. Some probes, like the one focused on Rajaratnam, rely on wiretaps. Others stem from a secret Securities and Exchange Commission data-mining project set up to pinpoint clusters of people who make similar well-timed stock investments."