rejecting candidates because of their neighborhood

A reader writes:

During a workshop I attended, an employment counselor mentioned that some candidates can be rejected simply because of their zip code. Apparently, some hiring managers will screen out applications when residences are in zip codes implicating problems, such as being chronically late for work. Is this something you've been aware of?

Not only am I not aware of it, but it would almost certainly raise legal issues if the neighborhoods being screened out happened to have predominantly minorities living there. But legal issues aside, it's obviously a terrible idea.

In fact, this is such a bad idea (and as far as I know, not a normal practice) that I can only conclude that the "employment counselor" at this workshop didn't know what the hell he or she was talking about. I'd love to know what else she told you.