There is also a very large and growing group of private sex clubs that, to avoid legal problems, do not operate in a specified location. These organizations focus on private parties in homes or rented facilities and make use of the Internet to build their membership. There is usually a small door fee and most are invitation-only. In addition to sexual orientation, these smaller groups often stratify on specific criteria, e.g., heavy men with beards or those who are HIV-positive. The first sex club of this type exclusively for African American gay men was Black Jack, started in 1986 by Alan Bell.