Wow, that's quite a task and quite a challenge @markwhittam! But certainly a worthy one.
Perhaps what we have here is really an invitation to have two linked responses: immediate protection, and long term protection, which would be quite different in approach.
I believe CPS and other organizations are most inclined to focus on what we might call the "low hanging fruit" (most vulnerable) so the overall objective is to have an organization that strives (eventually) to make ALL the "fruit" difficult to get to. But in the start, we can't help everyone, the first goal might be simply to start by setting very visible examples of "difficult fruit" so the world can see that there IS hope.
I won't repeat what others have suggested but having an active "task force" that's available to be "recorders" every time there's an incident would certainly be of value. Film it, record it, write it down — purely from a neutral "non-militant" standpoint.
We have some very talented developers here in the Steemit community; maybe an app could even be developed; a one-button "need help NOW!" that broadcasts to a network of volunteers within reachable distance.
As for longer term protection, that's more challenging. AND it's a long-term project. Unfortunately, it may require lawyers and some kind of centralized structure (an "organization") that has collective weight to bring to bear at anything from local council meetings to legislative hearings.