This document discusses the growth of open data in New York City from 2009 to 2012. It notes that the number of public datasets grew from 170 in 2009 to 750 in 2011. It also discusses the launch of NYC's open data portal nyc.gov/data and quotes Carole Post, the director of the Mayor's Office of Data Analytics, saying that while all data should be open, privacy, confidentiality and safety concerns must be balanced on a dataset by dataset basis.