I very much doubt you can find much, if any, and that’s my point really Fisherman - you can’t prove bias, (except BOS)
How do you
prove that you think you got harsher treatment or were discriminated against because you’re black, fat, female, smoker, gay, ugly, a biker? I don’t think you can.
I feel forced to give a 'for instance'

On a different level, I’ve seen it for myself in my work whereby a job is advertised. Everyone already knows who’s going to get the position but for legal reasons they have to go through the motions of advertising and interviewing etc.
Someone who has done the job on a temporary or none-permanent basis who is liked and has got to know the job has to be interviewed for their own job if or when it becomes permanent, and guess who ends up getting it?
It’s completely unfair on the hopeful candidates' and a waste of time, effort and expense but I promise you will not find a whiff of this bais going on anywhere and never will, but that's life...