 On May 13, 2007, OpenDNS launched a domain-blocking service to block web sites or non-web servers by categories, allowing control over the type of sites that may be accessed.The categories can be overridden through individually managed blacklists and whitelists.In 2008, OpenDNS changed from a closed list of blocked domains to a community-driven list allowing subscribers to suggest sites for blocking; if enough subscribers (the number has not been disclosed) concur with the categorization of a site, it is added to the appropriate category for blocking.