Some Indian prisons use Vipassana too. It was quite a
success!
Buddha's teachings direct at our mind, so anyone in any walk of
life or any religion can use it to increase their compassion and
wisdom which will in turn bring them peace and happiness.
If the way we practise Buddhism increase our sense of
differentiating, attaching to different labels and therefore making
us feel different or better than other people, leading to more
anger, self-righteousness, putting others down, arguments, fights
and wars then the understanding must be somewhere
wrong.