I grew up with the whole JW things crammed down my throat before I, as a teenager, finally snapped at my abusive, alcoholic mother and told her off. My dad backed me up fortunately. I hate that cult. But I cannot condone even sending my worst enemies to a fucking concentration camp.
They should, however, be investigated and arrested on a traditional, case-by-case basis. Most of those people are just idiots who really reject modern reality because real life is hard. The point is though, you can't just paint a whole group as evil and round them up. It's important to find the ones actually doing bad things and run their lives in particular.