Where Did The “Challenge Accepted” Movement Start?

Over last few days it seems as though every time I open my Instagram the majority of post are those black and white selfies of women with the hashtag “Challenge Accepted” . This got me wondering, what is this movement and where did the trend start? I heard something about women in Turkey but i figured I would research this and according to Glamour this is the real story:

"Here's what it is, for those who are unfamiliar: It starts with one woman posting a black-and-white photo of herself, then challenging other women to do it too, using the hashtags “challenge accepted,” “women supporting women,” and “black and white challenge.” The purpose is to show solidarity and strength among women—a visual display of female empowerment, if you will." 

The New York times says that more than 3 million people have used the hashtags which makes sense because it's everywhere!

As far as the Turkish women involvement  here is what Glamour has to say:"

"What women in Turkey have turned this into is great, but they did not start this trend or its more recent resurgence in the US, which spread here from Brazil.”