Iran has threatened to strike the US west coast with offensive drones in retaliation for American military operations, according to an FBI warning issued to California police departments.
This is an ABC News report and it reads to me like the kind of standard thing that police dept's would send out at a time like this, not some kind of imminent operation.
There is some risk-off trading on this and that kind of attack is the kind of thing that could draw the US into a long, messy ground war.
Update: This is what the report says: "Iran allegedly aspired to conduct a surprise attack using unmanned aerial vehicles from an unidentified vessel off the coast of the United States, specifically against unspecified targets in California, in the event that the US conducted strikes against Iran"
Update 2: The State Dept also says Iran and its allies may be planning attacks on US-owned oil infrastructure and hotels frequented by Americans.
