That is of course applicable if the IDENTITY of the indvidual claiming citizenship is known. In this particular instance, what you have is a CLAIMED identity, so I imagine the citizenship question is moot.
Note, please, that I have not commented on Obama, specifically, only on the prevailing American citizenship law as of the time in question.
Among the people concerned with Obama's eligibility, there is a broad misunderstanding of those laws. I am trying to correct those misperceptions.
I have not taken a position on Obama's status because, frankly, I don't know -- for sure -- what the circumstances of his birth were. I am fairly certain, though, that they are not as claimed. But I have no idea in which regard the public information is in error.