From my understanding, carbon fiber is extremely strong within its designed load parameters.  That means the directionality of the load, the amount of load, etc.  It is only when one goes outside this load design that you start to see failures (other than manufacturing flaws, but that could happen on any bike).  

For example, clamping a carbon fiber handlebar using a stem designed for steel/aluminum.  The style of clamp is wrong, and can lead to crushing the bar at the clamp.  Same applies for almost all clamping surfaces.  Most components are not designed to be clamped down on unevenly.

As for the frame and fork, as long as you don't run into a wall, for example, you are probably going to be fine.  Doing so would put stress on the fork in the wrong way, plus try to pull the head tube away from the top tube, a stress it is not intended to handle.

Now, to fully disclose:  I weigh 375lbs.  Carbon fiber bicycles are NOT designed for my weight, and quite frankly that scares the crap out of me.  As a result, I ride Surly bikes.  Chromoly Steel with high spoke-count wheels to feel safe.