Sex trafficking is the movement of women from one country to another, or within national borders, for the purpose of sexual exploitation. An estimated 4 million women and girls around the world are bought and sold either into marriage, slavery, or prostitution. An average of 50,000 people are trafficked into the US annually.
Human trafficking is the 3rd highest illegal income source in America today - behind only drugs and gun-running. Humans, unlike drugs, can be resold and reused, thus making them a more profitable commodity. Internationally, sex trafficking is a multi-billion dollar industry.
"Sex tours" - tours for men to go to 3rd world countries to visit brothels created especially for them. Primary destinations include the Philippines and Thailand. Women rescued from brothels often are afraid to return home and have no place to go.
Women who have been trafficked may wind up in countries where they may not even speak the language. If they have a passport, it's taken from them. They are forced to work in brothels, having sex with large numbers of men every day. Control is maintained by threats and intimidation, violence, starvation, etc.
Some women and girls are abducted, some are deceive offers of legitimate work in other countries. Some are even sold by their poverty-stricken families.