in addition to the above, A recruitment agent I know is getting excessively p*ssed off with being asked to fill available openings and providing suitable candidates, that are never called forward for an interview and then being told the opening is not available 'now' and having to go through the same procedure a couple of months down the line.
His take on it is that recruitment agents are providing data of 'potential candidates' available for a 'potential position' that does not exist, it is merely a way of providing data to negotiate current contracts down wards and leaving the employer in a position to re-negotiate rates with the line if your wont do it for 'x', there's 'y' amount of people right now who will.
Also, many jobs that they are presented with already have candidates selected, however, the employer is fulfilling requirements in advertising a job, even though, technically its not available.
it's p*ssing him off as if his company doesn't fill vacancies, they don't earn income either.