Some carbon stuff is probably a little more fragile than the metal counterparts (things like handlebars, those new fancy derailleurs, shift/brake levers), and you have to be a little more careful about not over-torquing anything that clamps onto carbon (stems, seatpost collars), but as far as frames go, a lot of accidents can cause major damage to all kinds of frame materials, and carbon is not necessarily more likely to be trashed. It really depends on the circumstances of the crash. I've had some crashes on my carbon frame with no problems. Some aluminum parts (shifters, rims) have had to be sanded down after being gouged up. The frames were fine... until I backed into something with one of them on my hitch rack. The bike swung into the steel post of the rack and was crushed.

I've seen an aluminum top tube ripped in half, carbon forks splintered, aluminum chainstays busted at the welds, aluminum crankarms snapped in half due to a flaw in the cast. I would treat all bikes and components carefully. Crashes and other accidents can damage anything.