The late 1990s and early 2000s also saw the creation of a number of shelters and rehabilitation programs for prostituted children, and the police began to actively investigate the issue. The National Human Trafficking Resource Center (NHTRC) was later established by the Polaris Project as a national, toll-free hotline, available to answer calls from anywhere in the United States, 24 hours a day, seven days a week, every day of the year. Operated by Polaris Project, the hotline was designed to allow callers to report tips and receive information on human trafficking.