In the simplest case, a smart contract would make it possible to lock out a driver whose authorization to drive a rental car had expired. In more complex scenarios, rental car companies could automate the operation of entire facilities.

From a legal standpoint, the system becomes a “person,” a virtual third-party enforcer that never sleeps. From a computing perspective, that “person” is actually a software agent. The use of agents will be essential to scaling recordkeeping and providing visibility to the historical record.

Source: Blockchain defined: PwC