I've played literally hundreds of hours of multiplayer videogames; HALO, Gears of War and tons of others, and more recently a couple dozen Battlegrounds. One thing always stays the same: people love to act like jerks to each other.
The biggest jerk things I've seen are enemy players waiting in the graveyard for people to resurrect (what we call spawn camping in other games) so that you are attacked/killed before you can even buff youself, or just dragging out a game (by the winners) that should have ended quickly, just for honor points. I've been on teams that were victims and the guilty. ( I got yelled at for saying to cap the final flag or to leave the spawn area)
EDIT - this wasn't supposed to be posted yet, but thanks to me doing this on my phone, I "oopsed" and here it is.