What is the ruling on using a phone stolen from individuals or from a non-Muslim government hostile to Islam?

It is not permissible to transgress against the properties of governments, even if they are disbelieving, because they have granted security and allowed entry into their lands. This implies an implicit promise to preserve their security. A Muslim does not break their promise nor betray their trust, as Allah Almighty says: (And fulfill the covenant; indeed, the covenant will be questioned) and (O you who have believed, fulfill [all] contracts). And as the Prophet, peace and blessings be upon him, said: (The signs of a hypocrite are three: whenever he speaks, he tells a lie; whenever he promises, he breaks his promise; and whenever he is entrusted, he betrays his trust).