Hopefully one was the really drunk young women behind my group who would just scream to scream and thought it was funny. Then would almost fall on us (her friends would have to pull her back) whenever she stood up. My group learned to really dislike that one even though there were a couple other very annoying ones in the group.
My opinion, it’s fine to sing along with the performance, but screaming the words as loud as you can just wrecks it for people around you when you drown out the actual singer. It wasn’t even singing, it was just screaming. And this isn’t the woman who was just randomly screaming.