It will be interesting to see how employers defend "no misdemeanors" as a BFJQ to bar a 50 year-old from working at the GAP because she was arrested as a teen for juvenile in possession of alcoholic beverage.
The few times I've dealt with the EEOC have taught me that they seem to believe that all employers are evil and it's their mission to punish them severely. But I have to believe this kind of hiring practice is probably going to be found discriminatory, and rightly so.
Most jobs in law enforcement don't have an up-front "no misdemeanors" disqualification. The FBI says no felony convictions, my former employer says no felony or class a misdemeanors (and at least 10 years since your conviction for anything class b), most agencies have similar policies.
As perverse as some of you may think this, as far as we are concerned it really is against the law even if you're not caught. So, we do get to ask you about every criminal act you ever committed, and use that as possible disqualifier. That means that the we reject 35 year-old applicants with no criminal record (i.e. didn't get caught), stellar academic and work records because they committed a felony at age 17.
There was probably a lot of self-selection going on, but we still rejected a lot of people for on-the-record convictions. There were plenty more for all of the "didn't-get-caught" crew.
[And then there were all the "gee, I didn't know that was against the law" people - caught many of them when we started asking the questions about their sex lives.]
There are a lot of people who have broken the law, but not all got caught. This kind of hiring practice seems to be more inclined to catch up the poor and less-sophisticated. The educated executive type is better able to keep his criminality hidden than those lower on the socioeconomic ladder.
If it's not discriminatory, then run everybody through polygraph and see what shakes out.