A pipe bomb was found in the mailbox of billionaire George Soros' home. : A pipe bomb loaded with explosive black powder was hand-delivered to the suburban New York City home of billionaire financier George Soros by a would-be attacker, prompting the FBI to launch an investigation into who would want to harm the philanthropist and political activist, a law enforcement source told ABC News on Tuesday. The FBI photographed the device and then detonated it near Soros' home in Katonah, New York, and were analyzing fragments to determine why the bomb did not go off, the source said.