About: http://webisa.webdatacommons.org/278639288

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	I think it is legal throughout the US. In Greece, for example, all textbooks are free -- although from what I understand their system is a disaster.
http://www.w3.org/ns/prov#wasQuotedFrom	stackexchange.com