That is a trick question. The public took notice in 2008 as the impact was felt economically. Most people in the world of finance grew concerned in late 2006-early 2007. The actual orgins of the crisis started with the creation of the CRA act in 1977 and was grealy accelerated by the expansion of the role of GSE's (Fannie Mae & Freddie Mac) throughout the late 90's and early part of the 2000's. This is a much more complex problem then most people realize. The impact of distortions in capital markets through gov't incentives is usually not realized immediately. Rather it builds over time.