State Department Denying U.S. Citizens Passports

Here's an interesting question. How do you do prove where you were born? The ACLU Blog reports The State Department is Denying U.S. Citizens Passports, specifically "U.S. citizens of Mexican descent who live along the border and whose births were attended by midwives or took place at a local clinic."

"If you’re unfortunate enough to fit into these two categories, when you apply for a passport, the DOS will likely question your U.S. citizenship, and tell you to submit a litany of other documents—including school records, a local newspaper’s birth announcement, your mother’s pre-natal care records, baptismal certificates, immunization records—all documentation that isn’t required of any other U.S. citizen applying for a passport, to prove your citizenship. After forking over as many of these documents as you can find, and often paying more fees—DOS will respond by abandoning your application and classifying it as "filed without action." Passport denied."

I can see that they might be statistical reasons to questions such applications, but I
thought a birth certificate was proof of where you were born. All passport applications require one of those. If you submit one and it's legit, what's the problem?