and is far more than 69 for AI (http://area51.stackexchange.com/proposals/6607/artificial-in...), 40 for ML (http://area51.stackexchange.com/proposals/7607/machine-learn...), 16 for NLP (http://area51.stackexchange.com/proposals/2761/natural-langu...), 5 for data mining (http://area51.stackexchange.com/proposals/4229/data-mining).
(The original blog author means Area 51, not StackOverflow per se.)