Second go and read on Wikepedia how social security numbers were generated prior to 1973 and have been generated since 1973 and you will know that this author is full of shit.
This is how we know.
Susan Daniels, a private detective stated it in her affidavit that SSAN 042-68-4425 belongs to Obama. When her affidavit first surfaced, the Obama social security number was blacked out ,but you could still make out the numbers underneath the blackout. Obama's social security number became common knowledge on the Internet. Not only is there an affidavit from Daniels, it has also been submitted in Federal Court documents as seen below: