But, as CBS News correspondent Sharyn Alfonsi reports, an increasing number of potential employers are accessing these profiles -- and using them to decide whom they hire.
Dunia Rkein is a college sophomore. She has a stellar resume and an Ivy League education.
"I'm applying for analyst jobs," she says.
Rkein also has a profile on Facebook.com -- just like millions of other college students. In fact, 7.5 million college students use Facebook.
Rkein agrees that the social-networking site for students consists primarily of pictures of people partying and says "I hope that employers aren't looking at it too in-depthly."
The bad news is that employers are doing just that.
Take Tim DeMello, who owns the Internet company Ziggs, which lets people post an online business-oriented profile that the company says will come up first in most Internet searches.
When DeMello was asked if he does an Internet search for online profiles when he chooses whom to hire, he replies, "Of course. Everybody does."
DeMello estimates that about 20 percent of companies are secretly scanning online profiles before they interview applicants. What they often find is shocking -- including profiles that detail drug use, orgies and illegal behavior.
"They come in all buttoned up, their clothing is meticulous, they spend years building this resume, and this person that's sitting there is almost entirely different than the person posting on these Web sites," says DeMello.
Many employers admit they've even learned how to access profiles students think are "private" -- and they're surprised by how many students don't care if everyone knows everything about them.
What most students don't realize is those party pictures make up their "online footprint" -- one that will follow them well beyond sorority row.
Take Rkein's pictures. They don't show anything lewd or illegal, but ...
"Within a short period of time, you could find these 83 photos on every search engine on the Web, and these 83 photos could be attached to your name for the rest of your career," says DeMello.
While some of her photos may be "cute," DeMello says posting these photos online is like "she's telling me a secret."
There are sexy photos of Rkein that don't exactly scream "CEO material"
"I think some of these sites out there are going to be the most expensive free Web sites to their careers that they've ever seen," says DeMello.
It might have cost Rkein a job.
"I think I'd have other candidates I'd probably talk with," says DeMello.
Says Rkein: "I really don't think employers should be basing their opinion on me on Facebook." But asked if she might edit it when she begins interviewing, Rkein says, with a laugh, "Perhaps."
If you're supposed to dress for the job you want, employers say some of these students really need to just put something on.