it depends if it is on multiplayer or not. if it is on multiplayer and local than yes.
No.
No
no you can not
go into to options to turn it off.
you can turn it off in Call of Duty Black Ops
You can turn them all off including the blood
no you can not turn it off because its part of the game
No
no but you can report them
Yes, when you start Black Ops if you want to filter graphic content like blood and gore. In the PC Version you can turn off the voices, but not the words only. In zombies though you can turn off language.
You can't turn off the cussing in Black Ops. One solution is to just turn off subtitles and mute the volume.
no you can not turn off the blood its part of the game