Amid heightened security alerts in the wake of news of a possible 9/11 anniversary attack plot, threatening messages were posted to the White House's Facebook page, NBC News reported. "We'll come back 11/9/2011 to kill u all," said one of the several messages, using the date/month formula much of the world uses to refer to Sept. 11. "We'll come to u white house sooooooooooon," said another. Earlier in the week, the tip for a "specific, credible" terror threat said that three men, two of whom could be Americans, might detonate a car bomb in New York or Washington. Although security officials in both cities were on high alert, they had no confirmation of the potential attack attempt and had found no signs of unusual purchases of bomb materials.
