[solidsnack9000]

Without filtering rules and sub-communities that are following them, it's just one big soup of encrypted stuff. Once you have people self-selecting into groups, the suspicious ones are going to stand out more and then those can be infiltrated directly. Cops do this already, anyways, joining leftist/rightist organizations, offering things "for sale" on Facebook that will attract certain groups, joining tech communities via consultancies, &c.