Source: Future Publishing / Getty A recent intelligence memo circulated by the FBI raised concerns that Iran might attempt a drone attack targeting California, but U.S. officials say there is currently no credible or imminent threat, according to CBS News. The warning comes amid escalating tensions between the United States, Israel, and Iran following recent military strikes in the Middle East. According to the memo, intelligence suggested that Iran had at least considered the possibility of launching a "surprise" drone attack from a vessel positioned off the U.S.