Have you ever been sent countless fake jobs and when you agree to take a call from fake job sending recruiter he purposely wastes 15 minutes of your time asking you about your previous position, who was your line manager, what was your line managers phone number (they're old friends blah blah blah)? If you haven't, then you wont' understand why they are so detested.

The above is something they regularly do to try and fish for corporate clients at the expense of job seekers.