One French activist said this week that she wanted to challenge the burqa ban at the European court of human rights. To do so she would have to provoke the authorities into arresting and prosecuting her. She would then need to be convicted and have her conviction upheld by the French appeal courts.
What, then, might the Strasbourg court say? Article 9 of the human rights convention allows freedom of thought, conscience and religion. Freedom to manifest one's religion is subject some limitations – but only to those regarded as necessary in a democratic society to protect the rights and freedoms of others.
There is no suggestion that these women pose any kind of terrorist threat, requiring them to be photographed. It is difficult to argue that I have the right to see the faces of women walking past me in the street – even though my inability to do so may perhaps limit my freedom to live in a secular society.