What is the ruling on living in a house that was nationalized and then became owned by the tenant?

The nationalization of lands and properties by regimes without fair compensation is considered forbidden usurpation (ghasb). It is impermissible to purchase or rent such usurped property, as doing so would be a participation with the usurper and an assistance to him in his sin and aggression. This is what Allah forbade when He said: "And do not consume your properties among yourselves through falsehood," and "And cooperate not in sin and aggression." The usurped property remains the possession of its original owner, and it is not permissible to engage in transactions with the usurper regarding this forbidden property.