While accurate and comprehensive data on sex trafficking is scarce due to the covert nature of these crimes, a 2011 study of 460 U.S. sex trafficking victims found that 54% of them were below the age of 18. Another study found that a significant portion of such victims are 11 to 13 years old. Contrary to popular notions, these studies and others have found that most U.S. sex trafficking victims aren't from foreign countries and low-income households. Instead they are often U.S. citizens/nationals from middle-income homes. The tactics of sex traffickers, warning signs of their activities, and rescue and prevention measures are detailed at the 2nd and 3rd links below.