When I was looking for work a few years back, I used Monster.com, and I found that most of the "job" listings were imaginary ones created by recruiters so that they could build up their inventory of resumes. Finally got a job through a friend having a friend being a manager needing a new guy.
THAT practice should be illegal. One of our parents found a part-time job by keeping an eye out on snagajob.com - and one of my neighbors found a position on craigslist -- both are free for jobhunters.
But it's quite possible that MANY online websites are deceptive in the manner you depict. That's just horrible, and I wonder how common it was with the old newspaper want ads.