Also might be just SEO squatting... May throw up a bunch of AdSense ads on their side, the fact that there is a duplicate site is a problem for you, do what the

Also might be just SEO squatting... May throw up a bunch of AdSense ads on their side, the fact that there is a duplicate site is a problem for you, do what the comments say with adversarial stuff and complain to as many parties as possible including DMCA, registrars and the Microsoft/Google deceptive Site lists, etc. Don't let your domain expire or you'll get it bought of you and content mirrored there too which is surprisingly common