Actual possession functions as ownership even without legal rights. [definitional]
Thieves lack legal rights over what they steal; nevertheless they are able to consume it and to exclude others from it, to derive income from it, and to alienate it. Each of these capabilities is an attribute of ownership. The lack of legal rights may reduce the value of these capabilities, but it does not negate them
XREF: Connects to de facto vs. de jure power distinctions, and to debates about property as social fact versus legal construct.
Diego Gambetta, The Sicilian Mafia The Busi…, loc. 824