The OCLC record usage guidelines state:

1. Each member and nonmember library may use records without restriction, and may transfer records of its own holdings without restriction to other libraries.

2. In addition to transfers to libraries, each member and nonmember library may transfer records of its own holdings without restriction, to (a) member networks, (b) state and multi-state library agencies and (c) all other noncommercial firms.

The Internet Archive (the nonprofit that's operating the Open Library) is both a registered library in the state of California and a registered nonprofit organization.