The trends of CP posting are like this:

1. Links obfuscated by URL shorthands. (tinyurl, anyone?)
2. Posting keywords like kids, and the like.
3. Posting from a country with zero contribution traffic, and those from unexpected sources.
4. These posts are surprisingly consistent in origin.

While it does pay to watch over the boards from time to time, safeguards would lessen the chances of you needing to login and clean up the mess.

From my experience, precise IP bans do the trick for CP posts. They usually come from Russia, but other origins have been noted too.