More than 9 million students—including about 100,000 in the DC/Baltimore area—have logged on to the Web site, creating profiles of themselves and posting pictures. While it’s mostly harmless fun, it’s trouble for university administrators.

The George Washington University student paper, the Hatchet, reports that a dorm adviser tried to punish students whose pictures on Facebook appeared to show them smoking marijuana. While the students weren’t reprimanded, because of lack of proof, other schools have used the Facebook to catch students in the act.

Chris Hughes of Facebook says colleges can do this: “It’s certainly not what we designed Facebook to be used for, but there’s not much we can do about it.”

For college-age children of celebrities, the Facebook can cause unwanted attention. Luke Russert, son of NBC’s Tim Russert and a Boston College student, got into trouble when Gawker.com picked up his Facebook photo—Luke in a hot tub surrounded by scantily clad coeds. The profile was quickly taken down. Phil Alito, son of Supreme Court nominee Samuel Alito, also had a profile up, blogger Wonkette revealed. It soon disappeared. Complicating matters, fake profiles have been created for everyone from first twin Jenna Bush to missing teen Natalee Holloway.

By changing their privacy settings, students on the Facebook can keep questionable pictures away from university administrators. Might be a smart idea for those college freshmen with photo albums titled “DRUNK PICS!!!!!”