PlayboyU is stealing a page from Facebook — Facebook circa 2004, that is — and launching a college-only social network, restricted to people with ".edu" addresses. With help from Ning, it's starting PlayboyU — but not, sadly enough, delivering the goods in the form of nude coed shots. No matter. The college-only restriction limits the potential audience. And why would college kids, when Facebook and MySpace exist, bother to sign up for this website? The association with a porn brand alone should be enough to scare most students off. One thing Playboy forgot: ".edu" addresses include professors and alumni, who might take an interest in students' extracurricular activities on the site. We're placing the site on immediate deathwatch.