Incoming college students are hearing the usual warnings this summer about the dangers of everything from alcohol to credit card debt. But many are also getting lectured on a new topic--the risks of internet postings, particularly on popular social networking sites such as Facebook and MySpace.com.

From large public schools such as Western Kentucky to smaller private ones like Birmingham-Southern and Smith, colleges around the country have revamped their orientation talks to students and parents to include online behavior. Others, Susquehanna University and Washington University in St. Louis among them, have new role-playing skits on the topic that students will watch and then break into smaller groups to discuss.

Facebook, geared toward college students and boasting 7.5 million registered users, is a particular focus. But students are also hearing stories about those who came to regret postings to other online venues, from party photos on sites such as Webshots.com to comments about professors in blogs.

"The particular focus is the public nature of this," said Tracy Tyree, Susquehanna's dean of student life. "That seems to be what surprises students most. They think of it as part of their own little world, not a bigger electronic world."

The attention colleges are devoting to the topic is testimony both to the exploding popularity of online networking on campus and to the time and energy administrators have spent dealing with the fallout when students post things that become more public than they intended.

Northwestern temporarily suspended its women's soccer program last spring after hazing photos surfaced online, while athletes at Elon University, Catholic University, Wake Forest, and the University of Iowa were also disciplined or investigated. At least one school, Kent State in Ohio, temporarily banned athletes from posting profiles on Facebook, and now allows them to do so only with restricted access.

Non-athletes at numerous schools from North Carolina State to Northern Kentucky have been busted for alcohol violations based on digital photographs. Students at Penn State were punished for rushing the field at a football game. A University of Oklahoma freshman's joke in Facebook about assassinating President Bush prompted a visit from the Secret Service.

"I think they don't realize that others have" so much access, said Aaron Laushway, associate dean of students at the University of Virginia, which first incorporated the topic into orientation a year ago.

Many colleges tell students they won't actively patrol online profiles to look for evidence of wrongdoing-- but they are obliged to respond to complaints (at Susquehanna, Tyree says, rival fraternities like to rat each other out by pointing out photos involving alcohol to administrators).

The real concern, administrators say, is the unintended off-campus audience.

Unlike MySpace--a social site that many incoming freshman are already familiar with--Facebook users generally need a ".edu" eMail address and can view complete profiles only of users at their colleges unless identified as a "friend" by the profile's owner. So most students feel confident they are addressing an audience of peers. They shouldn't be so sure.