About: http://webisa.webdatacommons.org/407072336

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	This would be a simple solution that would work on many surfaces, including most floors.Also, the article does not say, but it probably also has more than one camera inside so it can see in multiple directions at once.
http://www.w3.org/ns/prov#wasQuotedFrom	slashdot.org