There are certain examples of hiring discrimination which are pretty clear cut. I am not sure if the cases have been tested in court, however.

See for example http://www.psychologytoday.com/articles/pto-20030430-000001....

The paper is "Implicit Discrimination." Marianne Bertrand, Dolly Chugh and Sendhil Mullainathan; American Economic Review, 2005, 95(2), pp. 94-98.

if you have access. Unfortunately, I don't at this time.

The basic results are that a resume with a 'black' name versus a 'white' name (and no other difference) are far less likely to fetch callbacks. Further, there's no appreciable difference in callbacks for black candidates with increasing skills, whereas there's a drastic increase for white candidates.

There are many other studies, and then there's my own, personal experience, which I'm not about to get into.