I think that's the key. He didn't go to Columbia to hang out with Columbia students. It sure seems like he doesn't want us to know who he WAS hanging out with, and those people are apparently cooperating in keeping info about his Columbia years under wraps. I suspect it's because they were radical left-wing political activists, many of whom have since outgrown their youthful naivete and now hold respectable jobs, and are no more eager to have their past radical activities publicized than President Obama is. I wouldn't be surprised if there are also a handful who've been "encouraged" to keep quiet -- that would probably be ones who failed to move on to better things, and are thus easily hushed by helping them get jobs or apartments. There's probably at least one seriously unsavory person in the group he spent most of his time with (possibly one with whom he was romantically involved), and that would be the root of the desire to keep this period of his life under wraps.
Obama tells us that he went to the Marxist-Socialist conferences at Cooper Union and African cultural fairs in Brooklyn and started lecturing his relatives until they worried he’d become “one of those freaks you see on the streets around here.”
I neglected to mention in my previous post that Michael Baron has given $1,250 to Obama, so he’s an Obot.