These guys are using the Web to do good deeds: they're encouraging people to expose scams, tricksters, and other low-lifes by making their information available on the Web. Anyone can register with these guys and file a report on a multi-level marketer, fly-by-night shyster, televangelist, or what have you. The Web search engines then pick up these reports and make them available to anyone smart enough to search on the Web for their names.
Of course, there have been cases where people have falsely accused various groups and individuals of being con artists when they're actually on the level; and the Rip-off Report site has received several legal threats because of its activities. The folks involved with this site are doing their best to make sure the reports there are honest, and not simply being used to smear people.