As the youth, who was riding a motorbike illegally, waved and did a wheelie, the policeman raised his middle finger in reply. Unfortunately for the officer, he was pictured making the obscene gesture.
The footage was uploaded to the internet - prompting an investigation by his force. Some people insisted the officer should not be disciplined. And he found some sympathy from his own chief constable.
Chief Constable Dave Thompson said: "I feel the objective should be to find the thug on the bike."
The footage was uploaded by a group called Bikelife Birmingham, which posts videos of stunts online.
The force said: "This behaviour is unacceptable and falls below the high professional standards we expect."