Because chance are a prospective employer will look you up on it.
According to a study published in 2009, Harris Interactive found that 45% of all employees use social networking to screen candidates. That number jumps to 53% for professional services such as law firms. The top three social networking sites for employer screening are Facebook, LinkedIn and MySpace.
Employers reported that 35% of the time they found content that discouraged them from hiring candidates with the top three red flags being inappropriate photos, evidence of drug use or excessive drinking and badmouthing a previous employer. However, they also found content on those sites that made them more likely to hire someone, for instance a profile that documents the candidate’s relevant skills and talents or that the candidate’s personality seems like a good fit.