Human trafficking is a serious crime and a violation of human rights. It has been on the rise because of increasing mobility, the spread of internet use and the generally low risks and high profit involved. The true extent of the problem can only be estimated, as complete statistics are not available and data are difficult to collect. However, even without exact numbers, it can be observed that a victim's gender influences the likelihood, manner and purpose of their being exploited. Available data on the prevalence of human trafficking show that most victims are women and girls, although men and boys are registered as victims in increasing numbers, as are transgender people. Sexual exploitation is by far the number one purpose of trafficking in women, while forced labour is the main purpose of trafficking in male victims.