Someday before we have post a blog at What is HR , regarding the impact of social networking & received an encouraging responses, this is the abstract of that blog,

A Facebook profile can confirm a candidate’s qualifications (or lack thereof), inappropriate alcohol or drug use, swearing or bad communication or bad-mouthing of previous employees or workplaces. It could also uncover personal details that contradict what was said in a CV or interview. And while this type of screening would never be used as a deciding factor, but it gives employers the opportunity to dig a little deeper or ask for more references.