From King5.com:

ANACORTES, Wash. – A threatening message was posted on the Shell refinery’s Web site Friday evening.

The company did not reveal the contents of the threat, but authorities didn’t take any chances and they were searching the premises for any sign of a bomb.

The U.S. Coast Guard set up a marine safety zone 200 yards from the facility.

U.S. Coast Guard boats were patrolling the area Friday night, and the Skagit County Sheriff’s Department also was searching the premises, but so far there has been no sign of anything suspicious.

No evacuations have been ordered.

Shell has been the target of criticism by environmentalists, and a little over a year ago were told by the Washington Department of Ecology that their Anacortes refinery needed repair. In that report three oil spills from the refinery were preventable had the company kept the pipelines in better repair.

Shell has long been a target of radical environmentalists and anti-capitalists, it is likely the bomb threat came from a zealot from one of these movements.

h/t N.T.A.