For years this one man has taunted, threatened and frustrated the United States. But who is he? The U.S. government has tried to link him to nearly every act of Islamic terrorism against Americans in the 90s: from the 1993 attack on the World Trade Center, to the bombings of U.S. military installations in Saudi Arabia, to the 1998 bombings of two US embassies in Africa. [This is a post-9/11 update of an episode that originally aired on 4/13/1999.]

Sunday night, as U.S. bombers and cruise missiles attack targets in Afghanistan, Osama bin Laden released a videotape calling on Muslims worldwide to join his war on America. Next to bin Laden was his close association, an Egyptian named Ayman al-Zawahiri, a man who is certainly as important to the terror network as bin Laden himself. Tonight on FRONTLINE, the full story of these two men, the story of how the seeds of their hatred for America were sown not in Afghanistan but in two of the U.S.'s greatest allies in the Islamic world, Egypt and Saudi Arabia, and the story of how they joined forces to pursue a common enemy.

In "Dot Con," award-winning FRONTLINE producer Martin Smith takes an inside look at the precipitous rise and fall of the Internet economy -- and examines the allegations that brokers at some of Wall Street's most prestigious firms manipulated the hot IPO market of the late 1990s. Wall Street, of course, would prefer to forget the past. But investors and investigators want to know: During the headiest days of the Internet bubble, did investment banks and venture capitalists betray the public's trust? Did "irrational exuberance" give way to fraud?

Porn is one of the largest and fastest growing forms of media in the United States. The industry’s profits have skyrocketed as we become increasingly reliant on technology for our entertainment. Why has this happened, and will the trend continue?

In "Bigger Than Enron," FRONTLINE correspondent Hedrick Smith shines a spotlight on how the corporate watchdogs -- the bankers, lawyers, regulators, politicians, and above all, the accountants -- failed to prevent Enron and other scandals from happening. Through interviews with current and former SEC officials (including SEC Chairman Harvey Pitt and his predecessor, Arthur Levitt), Arthur Andersen executives (including former Andersen CEO Joseph Berardino), members of Congress (including Sen. Joseph Lieberman of Connecticut), investor advocates, and others, the report explores how the system of controls was eroded by conflicts of interest, as well as by congressional intervention that blocked efforts at protecting investors.

How the Israeli-Palestinian peace process begun at Oslo was derailed.