I responded to a recent blog post on LibraryThing which mentioned restrictions on the use of VIAF and its relationship to the LC authority file.
In fact, VIAF is open for use by anyone. Here's what I said about the use of VIAF:
VIAF is a project led by LC, the French and German national libraries and OCLC. There are no restrictions on its use. Dumps of the complete file are available, but need the approval of the project leaders.
VIAF is not designed to replace the LC/NACO authority file, but rather is built from it and a number of similar files.
I hope that is clear. We really do want people to use VIAF!