Seems they gathered the data themselves and releasing it public domain, so now it is. At least from what I can gather in https://news.ycombinator.com/item?id=22

Seems they gathered the data themselves and releasing it public domain, so now it is. At least from what I can gather in https://news.ycombinator.com/item?id=22174464 https://news.ycombinator.com/item?id=22174464