After the collapse in technology shares in 2001, Credit Suisse replaced CSFB’s CEO Allen Wheat with Morgan Stanley's John Mack, who was charged with turning around the investment bank. Mack fired 10,000 employees, or one-third of CSFB's workforce, although many former DLJ bankers continued to collect guaranteed pay long after they were gone. Also in 2001, the U.S. Securities and Exchange Commission and the Justice Department began investigating how CSFB allocated IPOs of technology companies. The probe led to the conviction of Frank Quattrone in 2004, who was found guilty of urging employees to destroy documents after he learned about the investigation. He was ultimately acquitted of substantially all charges upon appeal in 2006.