Years ago, when recruiting for a tech support position, I had an agency send a bunch of 'pre-screened and qualified' candidates through. Most were fine, and we could start straight away with conversations about debugging AUTOEXEC.BAT and CONFIG.SYS (this probably dates the time period!) One candidate, however, looked like a deer-in-headlights, and was clearly out of his depth. In the end, I asked "There is a computer in this room, can you point to it?", and he sheepishly pointed to the fridge!

I felt really bad for the poor guy; it was not his fault. We finished the interview early, had a friendly chat, and I sent him on his way with some bus fares.

I then got on the phone and tore the agency a new one. They had wasted his time, and my time, by 'doctoring' the qualifications. I never used them again.