You can find quite a few legitimate Amish e-commerce sites on-line. There has been significant Amish acceptance of the internet as a means to sell goods. Many of them have also embraced solar generated electricity. It's not ok to plug into the power grid but if god provides sun and sun provides electricity then electricity is apparently ok. I am pretty sure they could find a way to justify a passport if it were necessary. And if they were born on US soil they are most certainly eligible to apply for a US passport.