"Ownership" of this data is not clear to me. If FB does not allow large scale spidering/collecting of this meta data, then FB has the best use of it. On the other hand, if many other web sites use these meta data tags to be consistent with what is an ad-hoc standard, then anyone can spider 3rd party sites subject to their robots.txt file. Hopefully, by using the FB public APIs then developers can get sub-graphs of FB hosted data to work with.

I like standards, and I would like it if many people started supplying RDF for their sites. I am not sure yet if this advantage out weighs FB's lock on the best use of this data.