I want to know the answer to the following question:
What 2010 body found how difficult it is to accurately report the financial impact of infringement?
All the background I'm provided with is that "The U.S. GAO's 2010 findings regarding the great difficulty of accurately gauging the economic impact of copyright infringement was reinforced within the same report by the body's research into three commonly cited estimates that had previously been provided to U.S. agencies.". Is that enough to answer the question?