I don't know of a good way except to call them out publicly and label them what they are. 

Also important to build strong communities that refuse to accept that shit and then outlast the fools who get swindled by them. 

There is no short term solution that doesn't feel like hacking at the branches, imo. But long term I think consistency of message, calling them out, and showing and reminding everyone of the outcome over and over is the only decent option on the table.