David Boies is an American lawyer and chairman of the law firm Boies Schiller Flexner LLP. Boies rose to national prominence for three major cases: leading the U.S. federal government's successful prosecution of Microsoft in United States v. Microsoft Corp., his unsuccessful representation of Democratic presidential candidate Al Gore in Bush v. Gore, and for successful representation of the plaintiff in Hollingsworth v. Perry, which invalidated California Proposition 8 banning same-sex marriage. Boies has also represented various clients in US lawsuits, including Theranos, tobacco companies, Harvey Weinstein, and Jeffrey Epstein's victims including Virginia Roberts Giuffre.