Sexual slavery

1. Consensual sexual slavery (see for example BDSM, total power exchange)
2. forced prostitution
3. slavery for primarily non-sexual purposes where sex is common or permissible.

Forced prostitution

Forced prostitution is a form of sexual slavery that is often directed at immigrants to western countries. Often the "owners" of these people will confiscate passports and/or money in order to make the women involved completely reliant on them. This practice is universally illegal.

In the mid-19th century there was a white slavery scare which suggested that large numbers of white women were being kidnapped and forced into prostitution. The prevalence of this practice was greatly exaggerated due to xenophobia.