sports shooter himself, leading some to question whether the president had ever fired a gun. over the last few days, one major american media company after another has announced that it has been attacked by hackers, twitter says its system was broken into and we have heard the same from three of the nation's biggest newspapers. some of these companies suspect that china is behind all of this and nancy cordes has been investigating. >> twitter called it an extremely sophisticated attack, that may have compromised as many as 250,000 user names passwords and e-mail addresses. a top official at the social networking site posted this message. this attack was not the work of amateurs, he said, and we do not believe it was an isolated incident. twitter won't say who is behind the attack, but it is the fourth high profile hacking to surface this week. atto date the washington post revealed it too had been targeted following similar announcements from the wall