Yes, but to be honest Craigslist is getting the exclusive right to the specific posting. It doesn't stop me from making a new job ad somewhere else. I believe the crux of the issue is at the mark of creating the ad versus copying the CL ad and hosting the content somewhere else.

By creating the CL ad, I honor the fact that I don't go to site X and choose to 'import' my ad from CL. I just create a new one somewhere else, which delineates both of them as separate ads. Just my 2 cents