[delwin]

Any critique that world-class teachers give Khan Academy would apply to most K-12 math teachers as well. I think people are worried because Khan Academy can spread much further (and do much more damage) than a conventional teacher, who is fired if standardized testing scores drop below an arbitrary amount.

BUT the same effect is seen on Wikipedia, which has been reviewed and corrected more than thousands of other encyclopedias, simply because it's so open and accessible. Khan Academy was originally run by one guy, but they're starting to open up and partner with other educational entities. They aren't going to go unchecked. By no means is Khan Academy hurting the education system, unless you look at things from an economic or political standpoint, in which case it's potentially disruptive. But that would be cruel, wouldn't it?