Clandestine groups

A clandestine group is an organization or group of people who keep their affiliations and their activities secret, usually to avoid persecution by law enforcement. Though it is generally safe to assume that current groups with these characteristics would not be listed on Wikipedia (at least not prominently), historically-clandestine organizations that no longer exist and are of historical interest to Wikipedians are prime candidates for this category, as are current organizations that are partially clandestine and have no qualms about revealing the fact (in general terms) that their organization has clandestine elements, if any such organizations should choose to do so.