Cult of Justice, it'd work with three person cells, one person would be in charge and be part of a cell above that, where someone else would be charge there etc. Members would know only three other members at the most. But the higher you were you'd be able to send information and changes in strategy doctrine down the chain. Everyone would have a tattoo of the scales of justice with a sword in the middle hidden somewhere out of sight but revealable (like under hair etc, in between toes etc), if asked by none members they're told to say it's a just a dumb astronomy thing they got.
The goal of the cult...to fight crime (obviously).
How you do it is up to each individual cell, be it punisher style attacks, patroling the streets, high profile mob assassinations or volunteering at community centres teaching youth jobs, whatever. The cell system would allow information, missions and money to flow up and down where it's needed. Hopefully important members would join like Police, Doctors, Lawyrers and Politicians, so anonymous tips can be given, stuff covered up and important aid supplied.
In my inner circle we'd know a lot of our lieutenants but ultimately not all the members and they wouldn't know us. We have perhaps a hidden network for quick communication and assistance.
Captured drugs would be surrendered to the police anonymously, guns allocated to cells that desire them and money goes up the chain to be redistributed. I'd take enough to live comfortably and not have to work to support my, but most would be reinvested into cells and community projects.
So I guess it's more anti-crime terrorist organization/syndicate at the moment, so I'd have a whole bunch of rules, creeds and other stuff.