http://www.youtube.com/watch?v=gtqmDCEAiq8&feature=player_embedded  Hebah Ahmed blogger - Muslim Matter
 Born and raised in the US Hebah says she has a Masters Degree in Mechanical Engineering and much later in life decided to wear a niqab. She says that wearing a niqab has in no way made her feel oppressed or enslaved. 
 I have a few friends who wear the niqab, & everytime I have asked them why they choose to wear it - they say they like the feeling of being secure.