The Red Thread (De Rode Draad) is an organization in Amsterdam that exists to 'protect the rights of sex workers', in the city with the world's most famous (and quasi-legal) sex trade. It's staffed entirely by former prostitutes, and it's a cross between a foundation and a self-help group. They seem to have five main goals :

• Provide a place where prostitutes can come for help, should they find themselves in an 'undesirable situation' (maybe they were 'trafficked', meaning brought in to the Netherlands against their will to work, or more commonly, they are having problems with customers). They have a hotline and a staff to provide this.
• Provide information about STDs and preventative measures to both sex workers and customers.
• Provide across-the-board pressure to force prices up, and thus increase profits for everyone; The Red Thread claims that prices have not risen since the mid-60s, and that most prostitutes are extremely poor.
• Raise the quality of working conditions for prostitutes - either abolish or legalize and strictly regulate brothels, and establish enforced building codes (fire alarms, safety alarms, sanitary facilities) for sex workers. Force employers to add benefits such as sick leave and holidays.
• Provide information about the latest laws and taxes, and help pass legislation (usually laws to regulate the sex industry) that benefits sex workers.