(3/10/06) - With college basketball championships underway around the country, the FBI has warned stadium operators of a possible suicide bomb attack at sporting events. In a directive issued today, obtained by ABC News, the FBI says a posting on an extremist message board "advocated suicide attacks against sporting events as a cost-effective means of killing thousands of Americans." The FBI and the Department of Homeland Security say they cannot confirm the credibility of the threat or whether the message is affiliated with al Qaeda. The FBI says the Internet posting said the suicide attacks would be justified because the...