As far as I know, the controller of The Poloniex exchange has changed,They need new users!good luck！
who is the new owner? is not it the circle?
According to a pair of blog posts, Poloniex will now become Polo Digital Assets, Ltd., an independent international company backed by an unnamed Asian investment firm.
that's enough to answer your question. Some people said it has owned by Justin and that's true but he was one of the investors who was investing on poloniex exchange site.