Peer-to-peer file-sharing on the Internet has certainly weakened copyright, but that’s not necessarily a bad thing unless one equates « stronger copyright » with « better copyright. » According to the US Constitution, copyright is about promoting « the Progress of Science and useful Arts« ; it’s not about enriching authors, except as a means of promoting said « Progress. »
“Data on the supply of new works are consistent with our argument that file sharing did not discourage authors and publishers,” they write in their paper, “File-sharing and Copyright »
http://arstechnica.com/tech-policy/news/2010/06/file-sharing-has-weakened-copyrightand-helped-society.ars