The SoftBank Group's acquisition of semiconductor design firm Ampere Computing LLC could encounter prolonged and intensified scrutiny from the U.S. government. The Federal Trade Commission (FTC) has embarked on a thorough investigation into the deal, issuing a second request for transaction details. Such subsequent inquiries are uncommonly rigorous, and the probe may extend for a year or more, with the option of filing a lawsuit to halt the acquisition remaining on the table.