Strange Man Facebook Friending My Young Daughter and Her Friends, What Should I Do?

My daughter showed my wife the Facebook profile of a shirtless guy who'd sent her and five of her friends "Friend Requests." He appears to be in his late 20s and had about 375 friends. When we clicked on his "friend" list we discovered the vast majority of them were young girls between the ages of about 12 to 15.

Upon further research we found he had at least one other profile and THAT one was friends with over 300 young girls. We posted screen shots to our own Facebook accounts and a family friend said she thought he has at least a THIRD account with similar "friend" lists.