I’ve never seen any evidence of this happening in real life, but here on HN (and on Slashdot back when I read it) it’s common to see people insist that they would never hire anybody who _had_ any sort of certification. The reasoning usually goes something like “everybody I’ve met who had that certification was an idiot, so I can extrapolate that everybody who has it is also an idiot”.

Of course, there are people here who say the same about college degrees, too.