In certain places, wearing a Niq'ab is a security threat, which I can understand.
Like, my mum works at Vertex, a company which outsources work for the Child Support Agency, and you can't wear a niq'ab if you work there, because workers have access to highly sensitive documents, and because of the volume of people they employ it would be impossible to track someone with a Niq'ab on all day, thus they aren't allowed. I think this is a fair policy in places where the full niq'ab does cause security issues as it is a choice, as opposed to being religiously binding.
As a general thing, I think that women should be able to choose whether they wear them in the streets or not, but of course i think that no woman should be forced to wear it. I think Nicholas Sarkosy's plan to 'ban the Burka' is just as belittling to Muslim women as making them wear it.
Another thing I think that needs to be considered is that British people are likely to feel alienated from a culture that hides identities so well, as we are used to interacting with people where we can see their face, expressions and body language. Thus the headwear may cause segregation - however if the muslim community is prepared to sacrifice Muslim-British relations for the sake of wearing the headwear, then that is a decision that falls on them. However segregation and alienation often can lead to ignorance, and prejudice, which i think is something that women who wear this need to take into consideration when making choices about how it will affect them. (I use British as not all of us are Christian, i'm aware i'm comparing a religion and a nationality)
Have you done any of these?