Infinity Ward has published a Code of Conduct for Call of Duty: Ghosts, which explains how the developer will respond to different disruptive behaviors in the game.
Infinity Ward will make a concerted effort to curb "offensive behavior." It says that any user who is found to use aggressive, offensive, derogatory, or racially charged language is subject to penalty. On the first offense, the user will be temporarily banned from playing online, anywhere from 48 hours to two weeks. If the the user repeats this behavior, he can be temporarily banned again, have his stats reset, have his split-screen privileges revoked, and be blocked permanently from appearing in leaderboards.
Permanent bans, however, are reserved for different offenses, meaning that a user could conceivably keep harassing other players with vile language as long as he is willing to suffer the consequences.
Any user who is caught with pirated copy of the game will be permanently banned immediately, as will any user who is caught modding or hacking the game for a competitive advantage.
"Boosting," meaning users who collude to exploit the game in order to gain XP and other rewards, can be temporarily banned or have their stats reset, as do users who exploit bugs in the game code.
You can find the Call of Duty: Ghosts Code of Conduct on the game's official website.