Lee Gomes of the WSJ reports on the TopCoder contest, and comes to this conclusion:

The results have been carefully tabulated by a computer and, thus, are beyond dispute: Of the 48 best computer programmers in the world, only four of them are Americans. But what that bit of data says about the state of the U.S. education system is open to debate.

Hmm. So Lee, if I set up an online survey, can I take those results as representative? What you have here is a self selecting pool of respondents. You simply can't make the jump from a self selected pool to any kind of general conclusion.