Almost all employers discriminate to some degree, it's just an issue of what basis they are using to do it. And, then later, what defense/reason they use to justify it.
Lot's of places won't hire long-haired hippie freaks. On the other hand, I pretty much won't hire anyone who is not. I guess there is some sort of balance there, though I'm not sure what it is, other than the fact that straight, normal people are not near crazy enough to do this job in the first place, nor will they ever love it, and loving it is pretty much the single personality (as opposed to skill sets) trait that I'll judge by.
I always try to ask myself, what is it that this person really wants. And if all they want is a job, then I don't need them.
If you just 'want a job' then I ain't got one for you. And, pretty much if all you want is 'just a job' then I doubt that you're going to be the person I'll need for a week like last week, where we did five shows in a row, for a total of 96 hours on the clock in those five days. We ate there, drank there, slept there and showered there. I am told there are people who like to go home once in a while.
And all that is a form of discrimination. Just like the pretty solid 'no in-recovery' people requirements that are not written, but pretty much understood.
And no matter what laws are in place, there is aways a way - particularly in the hiring phase, particularly in an economy like the current one - to not select the people you don't want around. You're always going to be able to find someone with 'better' credentials, who thus is a 'better fit.' Or, and I've swung this way too - finding someone with 'less' credentials, who might also be a better fit. That I was needing/wanting someone who could be trained to do it our way, and who I would not have to re-train out of all the bad habits they had already learned. Either way, I could have made the case to any administrative judge or jury that my choices were only guided by what I felt was best for the company and not by my (considerable) personal prejudices.