About: http://webisa.webdatacommons.org/30863301

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	You need infrastructure, auditing, staff, etc to provide certs then you need to pay browsers vendors to store them in the browser, around $250K for IE for example although that number was a while ago.
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com