I was raised in this headscarf-wearing branch of the Exclusive Brethren but by the age of 20 realised their practices were not for me (refusing to eat drink or socialise with nonBrethren seemed to me to fly in the face of Christianity, plus a lot of nasty hypocritical power-play stuff goes on in there, to say nothing of 'different' or poor people being ridiculed... oh and there's the biblically-sanctioned racism and chauvinism
none of which I could bear to stand by and watch). Because the church does not allow dissent or debate, I had to leave - my parents, extended family, home, friends... I lost the lot. After some months of shunning me (my sister refused to speak to me when we accidentally met in a supermarket!) in some bizarrely misguided attempt to entice me back with their loving christian kindness, I was excommunicated and informed by two 'priests' of the church's decision. The children I had some years later, have no functioning relationship with their grandparents or multitudinous other relatives in the church, because of my "sin". Occasionally I have made the effort to take my kids to visit their EB grandparents etc, but the inability to socialise (on the part of the EB) makes it so bittersweet as to be almost unbearable. Confusing for the kids when they're small, too 
whereisthewitch, pardon me if you view what I have to say next as "judgmental religious scorn"
but in my considered opinion the REAL behaviour of the Excl Breth (they rebranded themselves as the PBCC when under investigation by the Charity Commission recently here in the UK) is dangerously cult-like. All is sweetness and light - in a very narrow sort of way - from them, until you disagree. After that, there is nowhere to go... it's their way or the highway, or worse! (They believe themselves to be the "highest court in the land" and will lie and perjure themselves and say the most dreadful things, if they believe their "assembly position" to be under threat.)
The current hoohah in the UK about some Muslim children being culturally isolated and subject to extremists in their education makes my skin crawl, when I think of all the thousands of EB/PBCC children being indoctrinated in their private schools (which are not inspected by Ofsted, incidentally: the Breth applied for and set up a separate inspectorate). These PBCC schools began to be set up around the late 1990s I think it was - before that, EB/PBCC children had at least a little interaction with their peers in the outside world when they attended normal 'worldly' schools.
I feel very sad when I think of all the lovely and loved family and friends I still have who are stuck in that group (approx 45,000 members worldwide, mainly in Australasia, the UK, Europe, Nth America, Argentina). Most of them are perfectly happy to be in there - they have known nothing else since birth. But from the outside, if you take off the rose-tinted glasses the PBCC website and their newly created PR-machine would have you wear, the view is not nearly so christian. Yes, they have their good points (e.g. EB are sometimes quite good employers).... but in no WAY is that - and a fear of upsetting any religious applecart - a good enough reason to allow them to continue closing off their cult (and siphoning public funds as a supposedly 'Christian' church). Have we learned nothing from groups like Waco? Do we only make 'child protection' noises if a faith school is Muslim?
NO Exclusive/PBCC child under EB rules for the past fifty years has been able to become a doctor, lawyer, pilot, train driver, architect or nurse etc... in fact few EB are allowed ANY sort of job with non-Brethren companies any more. They have closed themselves off so much in the past twenty years or so - despite recently being allowed to take up charitable activities to shush the Charity Commission enquiries - it really does scare me a bit, as to where my much-loved Brethren relatives and friends might end up.
IMO Jehovah's Witnesses, Scientologists and this (Raven-Taylor-Hales) branch of the Exclusive Brethren are all quite nasty ingredients in the same pot. An example of EB duplicitousness has just sprung to mind: If by chance an outsider should turn up to 'sit behind' at one of their gospel meetings these days, the men (women do not speak in church apart from announcing hymns) have a special 'plan B' preaching to quickly put in place, in which they are forbidden to mention their leader Bruce Hales' name. There is a LOT of smoke and mirrors involved in being EB these days... as this thread has already begun to demonstrate!
You did ask 