Stream-sniping, typically, involves playing on a server with a streamer while watching the livestream to gain an advantage. As you'll see in the first few clips of the video below, stream-honking appears to involve joining a server that a streamer is playing on, getting into a car, finding the streamer on the map, then holding down the car horn in their vicinity. When fired at, the honker will speed away and then attempt to re-follow the streamer for more ear-harming honkery.
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