Imagine you have a big juice box that you really like. Now imagine someone else really wants that juice box and tries to take it away from you. They might even throw something at you, like a rock or a bottle, to try to get you to give it up. That's kind of what happens at concerts when people throw bottles or other objects at the performers on stage. It's not safe and can really hurt someone. Plus, it's not nice to throw things at others just because you want something. So, throwing bottles (or other objects) at concerts is called bottling and it's not okay.