About: http://webisa.webdatacommons.org/208529431

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	They likely have agreements with many of the sites you visit and based on your IP address and other unique identifiers know where you have been irrelevant of if you logged in or not.
http://www.w3.org/ns/prov#wasQuotedFrom	slashdot.org