Tangent: This is a side-effect to how Facebook exposes Facebook ids. They expose system-wide identifiers. LinkedIn's API exposes user ids that are transformed b

Tangent: This is a side-effect to how Facebook exposes Facebook ids. They expose system-wide identifiers. LinkedIn's API exposes user ids that are transformed based on whoever is interacting with the API. My network graph could overlap with your network graph, but the overlapping people would have different ids.