Wow, that sucks. I thought maybe their domain was just pointing at your ip address, but it's not. You sure no one in your company set it up? It looks like an exact copy.
They're hosted at GoDaddy, I would contact them and see what's up.
Non-authoritative answer:
www.strip-kittens.com canonical name = strip-kittens.com.
Name: strip-kittens.com
Address: 64.202.189.170
OrgAbuseHandle: ABUSE51-ARIN
OrgAbuseName: Abuse Department
OrgAbusePhone: +1-480-624-2505
OrgAbuseEmail:
[email protected]