When connected to another player in a match, if you flick a ball (Sometimes other objects) Repeatedly in the same spot with the same orientation and placement, you'll have a significant reaction.

If you are host and are doing this, then eventually the other person will hear a rapid clicking sound, that sounds like half started impacts on repeat. Eventually they will be knocked ball with an extreme amount of force, often enough to send them through EVERYTHING. (You do not need to hit them with the ball/object, you can just point it at them)

If you attempt to do this on client side, you yourself will hear the click, notice some strange artifacts, and eventually send yourself somewhere at speed.

The pushback will only ever affect a client-side player. This is as far as I've tested un-reproducible in the gym/solo play.

I think this deserves consideration