While your friends might think that picture of you hugging a beer keg on your MySpace profile is hilarious, a prospective employer might not appreciate the humor as much.

Popular social-networking web sites like Facebook and MySpace are some of the latest vehicles that allow anyone who can use a mouse to create an online identity and interact with others. Problems, however, arise from the penchant to reveal a bit too much on these sites - committing the online equivalent of reading one's diary aloud. That might not be a big deal to the 20-somethings who grew up online. But the folks who can offer you your next job probably didn't. If they were to come across that spring break photo while doing their own sleuthing, they might think it unseemly.

Jeanine DeBacker, an employment lawyer with Wendel Rosen Black & Dean in Oakland, Calif., says she often cautions her clients - employers and their human-resource managers concerned about the legality of conducting online background screenings of potential employees - "to remember that people coming into the work force don't always know the proper way to behave. That's not new." The difference now is that youthful (and sometimes not-so-youthful) indiscretions are made permanent in cyberspace for all to see.

And don't think that HR manager you interviewed with has no business trawling through your Facebook profile or blog musings. According to a 2006 CareerBuilder.com survey of more than 1,150 hiring managers, one-quarter of them reported using search engines to screen job candidates, while one in 10 said they've used social-networking sites. The survey also found that more than half of managers have chosen not to hire an applicant after viewing their online profiles.

DeBacker recently spoke about this topic to members of the Northern California Human Resources Association, where she is a board member. Her message is one of caution to employers who want to dig up digital dirt on employees. Though she generally recommends clients not to use the semi-restricted parts of social-networking sites, if they are planning to search a potential or current employee's MySpace profile, tell them as much first.

Jeanine DeBacker: I know about stuff like that from articles I read. It's more anecdotal, like law firms checking out people's MySpace pages. I read about one recruiting partner at a law firm using his daughter's MySpace profile to check out job candidates' profiles. This is something human-resources people are very interested in, the idea of the private Internet and public Internet. Even the private social-networking sites have a public aspect to them because you can get into them with a [registration] password.

MySpace and Facebook both have terms of use that talk about what people who are members can use it for. Facebook says it's only for noncommercial use. But I read that someone from Facebook said he doesn't think that the employment background checks are a violation of the terms of use. But my caution on that is that I never want my clients to be an ancillary party to a dispute. I don't want them dragged into a lawsuit between a member of Facebook and the company. I recommend against using the private parts of social-networking sites. I like to caution people even though everyone wants an absolute prohibition. I don't give an absolute prohibition.

JD: The first thing I say to clients is: "Aren't you thankful you're so many years out of college and you don't have all these 'opportunities' to socially interact?" I also say "how long are you going to punish someone for their lack of judgment." Now people are using these sites that make [themselves] permanent and accessible to the world. People in the 1970s were probably doing equally idiotic things but they didn't have the means to memorialize and disseminate it the way people do now. You had to take a picture, print it up, ride around on your skateboard and post it on a telephone pole for people to see it.

I also caution my clients to remember that people coming into the work force don't always know the proper way to behave. That's not new. They don't seem to know that they shouldn't wear clothes that show the new tattoo on their lower back. Actually using the Internet to look at information on current job applicants comes down to boring stuff: Are you making a decision based on valid predictor skills you think you need, or some other prohibited criteria or some sort of bias you have, or a "protected class." For example, you look someone up online and pictures show up of a female applicant and her girlfriend. In California, it's prohibited to discriminate based on sexual orientation. In interviews, the same laws apply.

When I'm talking to HR people, it's just a reminder that one reason to think about not looking at certain sites [when doing background checks on applicants], is that you can't un-ring the bell. You want to make a decision based on their qualifications.

Then there's also the National Labor Relations Act, when we're talking about current employees.... If you're doing lawful conduct during nonworking hours, it may not be something an employer likes, but the employer is prohibited from taking adverse action. The final part I talk to people about is the expectation of privacy.... A lot of people recommend you meet the person during the interview process; and if you want to go forward, you get written consent that your background check will include an online search.

Some employers have a lot of forms, and are very form-intensive. It's one way of [protecting themselves]. One way you lower people's expectations of privacy under federal and state law is to give them notice of what you're doing. People have a certain right to privacy protected by the Constitution. But the way employers can infringe on that is if they inform [job candidates] that they should have no expectation of privacy.

JD: I had a client, one of whose employees, a woman, looked up all other employees on Google. Then she went to check if they were on Megan's List, if they were a registered sex offender. There's a Megan's Law web site; it's kind of private, you do have to register.... She found a co-worker listed there and she demanded that person be fired. It's illegal in California for an employer to fire an employee who's on Megan's List [unless it's a school]. Then she refused to come into work, she didn't want to work with this person. We delved deeper and found they had never met in person, they didn't work physically near each other. She had taken it upon herself to look at the backgrounds of her co-workers. It took some effort to quell publicity about that.

People talk about using Google [for screening purposes] all the time. I've had people ask me if they can use their child's MySpace password to look up profiles of job candidates. I recommend they don't.

JD: The great thing about America is that there's freedom of speech, but not freedom of consequences from speech. It's well within an employer's right to make a decision based on what they find - as long as it's not based on the "protected classes."

JD: Like a lot of things on the Internet, there's no black and white. It's a slippery slope, a gray area. Not to be too Pollyanna, but employers should be making decisions based on whether the person has skills to do the job. We have procedures in place to do background checks to make sure their resumes are truthful or to find out if they're omitting things from their job history. Even though there are all these new and exciting ways of finding information, employers still should be doing things in a traditional way, based on merit