Not all heroes wear capes, as the saying goes.
Swedish BlackVue user Ronén shared the video he took with his BlackVue DR900S-2CH (available for purchase here). In the video, he spots and passes a van with a driver in a clearly inebriated state. As the driver poses a threat both to himself and to others, Ronén decided to contact the police and follow the drunk driver until the police arrived.
The driver was taken into custody, and the car was left abandoned at the scene.