I sort of wonder, too.
A few years ago they were right in the middle of town. Occasionally, I would see them in their hijab and robes, talking on their cell phones. I always walk away from them because I don't want them to see the disgust and contempt I have for them by my facial expression. I have a feeling they do a lot of what they do is just to shock people and get a reaction. I try to deprive them of that.
I stare them down and purposely give them the evil eye. I've had it with them and I'm not gonna hide it anymore.