Despite the protestations of the clueless twit over at Owen's place (hint: try the initials "RS"), it seems that pulling the visa was very, very do-able.
(Visa Reg 214(b))
That law requires an applicant to show strong roots in his home country — such as a house, a spouse, and/or employment — in order to prove that he would be likely to return home when his visa expired.
Young, single, unemployed men are the people most often refused visas under 214(b) (when it is actually enforced) for the very reasons that al Qaeda recruits them so heavily: They are shiftless and have very little to stop them from packing up and moving to a new country. There’s also, sadly, very little to prevent them from committing terrorist attacks.