In other words, this company apparently thinks that unfortunately jobless people are likely to have a work ethic and skills that are below those of employed people. Not only is this archaic thinking in the economic recession of today that has left thousands of good and hardworking people unemployed, but I think we all have had lazy or incompetent co-workers that sufficiently disprove this assumption.
If an employer is not willing to give perfectly qualified candidates a chance, simply because they are not currently working, then they are contributing to the unemployment rate they discriminate against, and that is just plain bullshit. It reminds me of other nonsense I've seen in job postings, like requiring a degree for an office assistant position, as though it takes four years of college to figure out a fax machine or copier. I understand that companies want experienced and reliable workers, but all of us had to start somewhere and even CEOs weren't born into their job.
I don't believe there should be laws against these kinds of discrimination, but it does baffle me that there are job ads like this, even if they are from smaller companies. It's so counter-intuitive: the unemployment rate cannot improve unless the unemployed are given jobs!