Where I think Government can get involved is when the Cult demands the shunning of family members.
What's the limiting factor here? And if it does get involved, is the stage set for some pretty bad unintended consequences? Is there, on net, more harm than good?
This results in breaking up family networks and has a detrimental effect on Society. A family network is a positive for our society.
True, but I can think of several political ideologies that are bad for families, some explicitly set out to destroy families. Perhaps we can sue those organizations for holding such beliefs.
When Cults wreck this family arrangement often the outcast members become a burden on Society
As if there sits a shiny, strong, cohesive family, and this religion (an external force) comes around and wrecks it? No, the family is made up of people, each with a choice. The hard pill to swallow, IMHO, That's the hard pill to swallow - the realization that your family doesn't actually love you like you thought they did. "Oh no, its the organization! Because my family would never do such a thing on the own." Yes they would. They do all the time. It sucks. The DFed shouldn't let them of the hook so easily.