A variation on the Teabag. With this you swing your balls at the webcam for the benefit of the other people in the video chat. The webcam teabag is often done to shock and prank. For example, opening a video chat to discuss the next days economics assignment, but then the other person just sees all balls.
"I thought Steve was starting a video chat so I could see his new Futurama poster, but he ended up just webcam teabagging me."