Yeah, they can, it all depends on how clumsy you are parking lol. I've got a bit of curb rash from the previous owner where you can tell they ran over a parking stall. As long as its a quality kit from a good manufacturer (which duraflex is), you shouldn't have to worry about it breaking.
Also, welcome to Focus Fanatics!
ROTM June '13, PNW Crew #42, SR #245, Rally Rev #02