I keep reading/hearing about how recruiting using social networking sites (SNS) opens employers up to discrimination lawsuits because of who uses the sites. For the most part, this just plain isn't true.
A recent Pew study is the latest to show that when it comes to using SNS like Facebook, MySpace, and LinkedIn, you really should have one primary demographic concern when it comes to ensuring a diverse candidate pool: age.
Not gender, at least not in traditional sense. While four years ago SNS users tilted slightly male (55%), the balance has essentially flipped today (54% female).
Not race, there simply do not appear to be generalizable differences in racial groups when it comes to these sites (in fact I've seen some data that suggest the user base on these sites is more diverse)--but things change, and this may vary with particular sites, so keep an eye on this one.
But when it comes to age, SNS users are disproportionately younger than the overall Internet population. In the words of the Pew report, "[this] doesn't mean that more older adults aren't flocking to SNS--they are--but younger adults are ALSO flocking to the sites, so the overall representation of the age cohorts in the SNS user population has actually gotten younger."
One demographic difference I don't see a whole lot about: disability status. Are individuals with disabilities more/less likely to use SNS? I think that's an important question we need to address if we're truly trying to diversity our candidate pools.