WILMINGTON, Del., Jan 4 (Reuters) - U.S. prosecutors told a U.S. judge on Wednesday they are in the process of seizing shares of Robinhood Markets Inc that were allegedly pledged as collateral for loans to Alameda Research, which was founded by Sam Bankman-Fried, who has been charged in the collapse of cryptocurrency exchange FTX. (Reporting by Tom Hals in Wilmington, Delaware Editing by Chris Reese)