Treyarch's Security and Enforcement Policy for Call of Duty: Black Ops 2 can serve as a guide to keeping you playing and safe from bans. Most of the rules are simple: don't use any hacks or modded code, don't use "unsupported" external hardware or software, don't be offensive or racist.
With the new livestreaming functionality comes a few new rules specific to it, though they cover familiar territory: "Any user who is found to have offensive or unauthorized content in their live stream is subject to penalty," Treyarch warns. "Offensive content includes but is not limited to foul language, racially charged language, and nudity. Unauthorized content includes but is not limited to unlicensed music, TV shows, movies and brand logos." Minor offenses will result in temporary bans from streaming; "extreme offenders" will be reported to streaming providers (YouTube) for account deletion.
Consult the full rules here, and don't be the kind of person who needs to consult the rules.