There was a program on yesterday evening on Four Corners, Australia's leading public current affairs program.
It was on the Exclusive Bretheren, a group very similar to the jws; fundamentalist, literalist, authoritative, family splitting, assisting to deny shunned partners any child custody etc. etc.
The group is smaller, and on that basis I think able to maintain more strictness.
Those who left had a saying for what keeps others in - the three F's - fear, family, finances