This revelation surprised a lot of people on the Street who thought all the exchange horse trading of 2010-2011 was over. In 2011, for example, the Justice Department blocked ICE and Nasdaq's attempt to buy the NYSE. NYSE was also stopped from merging with Germany's Deutsche Borse.
Read more: http://www.businessinsider.com/new-york-stock-exchange-acquired-2012-12#ixzz2FbY1vfFi