I didn't have a passport until I was six or seven, and until then traveled on my mother's passport -- her photo included me, her, and my sister. But back then

I didn't have a passport until I was six or seven, and until then traveled on my mother's passport -- her photo included me, her, and my sister. But back then the photos were bigger. The article doesn't point out that passports were introduced on a temporary basis during WWI, and most countries that issued them did indeed do away with them at the end of the conflict. However they remain a prominent example of scope creep.