The regime couldn't have possibly tracked down every single person Obama ever knew, and forced them to sign a non-disclosure agreement. There's no way the empty headed choom smoker could have even remembered everyone he ever knew.
Someone out there has to know something about the guy. Still, it's pretty odd that few outside of Jeremiah Wright, Moochelle, and Bill Ayers claim to have known him before 2007. I'd have to agree with you that a whole lot of people have been silenced.
I got someone for you. Let me dig her up.