The department says it received a “possible threat” at 7:10pm. The threat was “determined to be unsubstantiated and not credible” and Facebook employees “began to leave the campus normally” at around 8:30pm.
The statement does not specify the nature of the threat, but the San Francisco Chronicle reports that it was a bomb threat.
The full statement reads:
On March 11, 2014, at about 7:10 p.m. the Menlo Park Police Department received a possible threat to the Facebook Campus in Menlo Park from the San Francisco Police Department. Based on this possible threat, the Menlo Park Police Department followed standard operating procedures and sent officers to the Facebook campus and advised Facebook personnel. Facebook personnel held employees at the site until officers were on scene. The threat was determined to be unsubstantiated and not credible and officers began to clear the scene at about 8:30 p.m. Facebook employees then began to leave the campus normally.
At this time, the threat received has been determined to be unsubstantiated and not credible. Any inquiries about the threat should be forwarded to the San Francisco Police Department.