Mary Forgione, a US citizen, was stopped and detained by Turkish border patrol when she attempted to reenter Turkey while on vacation. She wrote about her interesting experience for the LA Times. Takeaway: the State Department won't help you if you get detained in another country because a border agent forgot to stamp your passport.
Were's your other passport?" the border agent at Istanbul's Sabiha Gokcen airport snapped as he waved my U.S. passport.
He was annoyed, but so was I. I didn’t have another passport. The one in his hand was it.
"You came to Istanbul, you didn't exit and now you are re-entering,” he said slowly, his tone serious. “Where were you?"
But I had exited. Eleven days earlier, I had sailed from the city’s Karakoy port with a group of college friends on a Mediterranean cruise bound for Rome, I told him.
He shook my passport again and said, "Show me! Where does it say that?"
I looked in vain at the pages as he kept hold of my precious U.S. passport. He was right. I didn’t see any stamp that showed I had left Istanbul.
I didn’t understand how this had happened, but he did — or at least he thought he did: He decided I had a second, secret passport that I was hiding. But I didn’t.