here's a podcast on this very subject: Its actually really interesting. http://www.npr.org/blogs/money/2013/10/04/229224964/episode-489-the-invisible-plumbing-

here's a podcast on this very subject: Its actually really interesting. http://www.npr.org/blogs/money/2013/10/04/229224964/episode-489-the-invisible-plumbing-of-our-economy http://www.npr.org/blogs/money/2013/10/04/229224964/episode-...