Not sure where in the UK you live, but most British Pakistanis live in neighbourhoods full of there family or clan. I know for a fact a lot of girls wear the Hijab just so that they are a not a victim of gossip. In Pathan communities, many girls ARE forced to wear the Burqa. Most young Brit Pakistani can bearly string a sentence in English, let alone complain directly to the authorities.
But I still think this law is stupid, and any social change has to come from with in the communities.