About: http://webisa.webdatacommons.org/41304826

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	it is freely available under a BSD license, and is a start towards the sort of thing your looking for.
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com