Survey: Many hiring managers check out candidates' online profiles

The practice of performing impromptu background checks online is become more common among hiring managers. Are they in danger of breaking the law?
About 22% of hiring managers say they look for job candidates’ profiles on social networking sites, according to a recent survey by CareerBuilder. That’s up from 11% who said they did so in 2006.
Also, 9% said they’re probably going to start using the Web to help in hiring decisions.
How are they using the information candidates post? Of the managers who check the sites, 34% said they’d found cause to remove an applicant from consideration. Most of the time, it was because the candidate talked about drinking or using drugs, posted inappropriate pictures or had noticeably poor communication skills.
On the other hand, roughly one quarter of those managers found info that solidified their decision to hire someone, such as background supporting their qualification for the job, creativity, diverse interests and a general professional appearance.
Any problems?
Of course, the big question on HR’s mind: Are there any legal dangers or other problems to worry about?
There is the possibility of a manager learning about a candidate being in protected class, which could result in a bias claim if the person isn’t hired.
Beyond legal concerns, there’s also the danger of mistaken identity, especially if the candidate has a common name. Also, some argue that what someone posts online won’t necessarily have anything to do with their job performance (even if they were dumb enough to put questionable items online in the first place).
What do you think? Have your managers ever checked out applicants on the Web? Do you think it’s a good idea, or a terrible one? Let us know by leaving a comment below.