I didn't have one until in was 15. My dad was forced to because he couldn't claim me on his taxes anymore when the IRS made it mandatory. "That was the year seven million children vanished," according to the IRS at the time.

The frustrating thing is that he was so vehemently against it, my mother had to do it (she controlled the finances), and this led to a huge issue because I was born overseas for my dad's work. They had to drag out state department records and proof I was a US citizen, because of being born on foreign soil. It was a mess.