Matt Damon, Ben Stiller and Ben Affleck were among the young Hollywood stars allegedly scammed by high-flying Wall Street broker Dana Giacchetto, 37, a Prada-wearing fund manager who is due in Manhattan Federal Court today. The feds are accusing Giacchetto of fraud, and he could get up to 10 years for running what is being described as an elaborate shell game. Giacchetto -- who used to party with Leonardo DiCaprio, spend vacations with superagent Mike Ovitz and Courteney Cox Arquette and her family, and reputedly provide stock tips to Q-Tip, Cameron Diaz and Gwyneth Paltrow -- allegedly misappropriated money from his clients' accounts into another account, which, investigators say, was then used for such things as paying Giacchetto's personal credit card bills. Among the broker's client list and the sums involved, according to documents filed by the U.S. Securities and Exchange Commission: the rock band Phish ($4.7 million), Courteney Cox Arquette ($825,000), Lauren Holly ($300,000), Ben Stiller ($250,000), Matt Damon ($100,000) and Ben Affleck ($20,000). That's an awful lot of credit card bills.