Some of the streaming music services do something like this. They scan your local music library and unlock those tracks to stream regardless of your subscription accesses. I used Google Music for this a while back.
Mp3.com That was attempted back in the day with CDs. It did not end well.
"To make the service easy to use, MP3.com did not require users to load their own music into the virtual lockers. Rather, a user merely had to insert a copy of the music into the CD-ROM drive of a computer, at which point MP3.com would verify that the person had possession of a CD, then the company would automatically put a copy of the music into the person's virtual locker."
"However, the lawsuit by the record companies asserted that MP3.com had violated copyrights by creating the digital database of albums to which they held the copyrights. In April, U.S. District Judge Jed Rakoff ruled that MP3.com had infringed companies' copyrights."
"In the ensuing months, MP3.com reached settlements with four of the record companies, including Sony Music, Time Warner, EMI Group and Bertelsmann. Details of the settlements were not made public, but analysts estimated the company paid $20-million to each company."
