I don't know why people hack & grief in most servers. It's very anoying to people who wanna play a normal, none-hack match. I have some reasons below:
HACKS:
1. They want to kill more than others.
2. They think hacks are cool (maybe).
3. Being a boss of the server (like being immortal and invurnable, if no admin is here).
4. Want to be a pro (that's false).
5. For fun (wtf why?)
MY COMMENT: Hackers are obviously noobs, no skill, bad and being hated. I wish some program that disables hacks if activated. No good ^.
GRIEFERS:
1. Revenge.
2. Goin to another team and grief there to make his/her team win.
3. Angry/mad (TO GRIEFERS: U mad bro?).
4. Complaining to his/her building and is not a good idea (he/she want his/her building to be there).
5. (Same as number 5 on hacks)
MY COMMENT: Griefers are no fair, though they might be on the enemy's side, or just a hostile team mate. They should go to it's team and play normally, not griefing.
Hope you understand, they're just my opinions. post here for suggestions and comments about this thing. ^_^