[pangram]

It definitely happens; here's a case from last year that the ACLU was looking at: http://www.aclu.org/blog/technology-and-liberty/want-job-pas...

The insidious thing about this is not if it happens for people looking for tech jobs (they're generally clued in enough to refuse, or go somewhere else, or make a fake Facebook account filled with stuff like "I love working so much!" and "I saved a man's life with a quick appendectomy at my volunteer gig"). People looking for lower-tier jobs are in less of a position to be able to refuse.