FBI agents searched the headquarters of a California solar firm that received a $535 million federal loan before filing for bankruptcy last week. Solyndra was touted by President Obama as a model for government investment in green technology. An investigation by ABC News and the Center for Public Integrity beginning in March reported that one of Solydra's lead private investors was Oklahoma billionaire and major Obama fundraiser George Kaiser, raising questions about the role political influence may have played in Solyndra's selection.The FBI wouldn't provide any details on what they were searching for or why. The company and federal energy officials blamed Solyndra's bankruptcy on intense competition from China.