-Using Default weaps when you have no GP.
-Map glitches that also like shooting through walls.
-Someone accusing you of hacking and getting mad about it when they are hacking as well.
-AFK Room masters
-Inability to kick users from room (should be master's job)
-Nexon banning the wrong people.
-People tossing in incendiary nades into your spawn point.
-Not using hacks, being called "chammer" "turn off chams noob" when your not, and they just suck hairy monkey cock.
-Being new to the game (first time player, new acct, all that) and being called a noob. Which clearly we are all noobs, hence why were all recruits and trainees n' such
-People bitching about nade spamming. I figure whatever gets the job done is fine. Even if it means spamming nades. (Not like you have many to spam anyway)
I'll add more later :P