Google's authorisation system Zanzibar (https://research.google/pubs/pub48190/ https://research.google/pubs/pub48190/) is not explicitly using SPARQL, but it's

Google's authorisation system Zanzibar (https://research.google/pubs/pub48190/ https://research.google/pubs/pub48190/) is not explicitly using SPARQL, but it's a good example of the sort of thing that a graph-based data model can do. I _think_ Zanzibar can be implemented with SPARQL: we implemented something very very close (and more powerful in some ways) with it