Ashton Kutcher and Demi Moore state this as part of the "Real Men Don't Buy Girls" campaign.
CNN -
There's between 100,000 and 300,000 child sex slaves in the United States today," Ashton Kutcher tells CNN's Piers Morgan. "If you don't do something to stop that -- that's when there's something wrong with you.
It has been repeated in numerously, e.g. USA Today
Ernie Allen, president of the National Center for Missing & Exploited Children "Each year, 100,000 to 300,000 American kids, some as young as 12 years old, are exploited in the sex trade"
The study (The Commercial Sexual Exploitation of Children in the U.S., Canada, and Mexico), released Monday, reported that 300,000 to 400,000 children in the United States — 1 in 100 children