From Snopes  This fantastical tale about President Barack Obama’s having used a Social Security number (SSN) issued to a French immigrant named Jean Paul Ludwig, born in 1890, is easily debunked. As can be verified through the Social Security Death Index (SSDI), a database of death records created from the United States Social Security Administration’s Death Master File Extract, the Social Security Administration was in fact informed of Ludwig’s death, and the Social Security number assigned to him was not, as claimed, the same as that assigned to Barack Obama (042-68-4425), but rather a completely different number (045-26-8722). Ludwig also didn’t pass away until 1981, by which time Barack Obama had long since been assigned a Social Security number of his own. And then they go on to actually show you how to look it up yourself.. kek