EXCLUSIVE VIDEO INSIDE THE WORLD OF THE SOMALI PIRATES -- WHO ARE THEY? WHY DO THEY TERRORIZE THE HIGH SEAS? WHO ARE THEIR VICTIMS? -- ON ABC NEWS' "20/20," FRIDAY, APRIL 17

Plus: A Brian Ross Investigation into the Business Practices of AIG

And: Monica Seles Speaks Candidly About Battle with Food and Depression Following Attack by Deranged Fan

Somali Pirates terrorizing foreign vessels and hijacking dozens of ships so far this year, including American vessels, have made worldwide news in recent weeks. Who are these pirates attacking these types of ships and how do they do it? "20/20" takes viewers inside the world of such pirates with exclusive behind-the-scenes documentary footage. Also, John Qui�ones sees first-hand how merchant marines are trained to defend against pirate attacks on the high seas. Additionally, Jim Avila reports on the private citizens who have been victimized by pirates, including the American captain who was just rescued by the U.S. Navy. The reports air on "20/20," FRIDAY, APRIL 17 (10:00-11:00 p.m., ET) on the ABC Television Network.

Also: A Brian Ross investigation � did AIG, the insurance company that had enough money for private jets, luxurious spa retreats for executives and millions of dollars in bonuses, have a policy of "deny and delay" with respect to insurance claims from Americans injured while working for U.S. government contractors in Iraq, including, for example, refusing to pay for a new artificial leg for an amputee? As part of a joint investigation with "20/20," Pro Publica and the Los Angeles Times analyzed more than 30,000 claim files. Ross reports a rare glimpse into the business practices of AIG.

Plus: Elizabeth Vargas interviews tennis sensation Monica Seles, who speaks candidly about the psychological aftermath of being stabbed by a deranged fan and about her father's death. For the first time, the nine-time gram slam champion who once ruled women's tennis details her off-court battle with depression and food addiction, and how she finally fought back.

"20/20" is anchored by Elizabeth Vargas and John Stossel. David Sloan is executive producer.