The HR dept at work looks thru social media outlets to ween out candidates. They use it as a way to see a persons true character (ie BAD character). Some people are very stupid and it’s HR’s job to keep them away from the hardworking, intelligent ones.
I’m in the legal field. We Google people all the time for a variety of reasons.
Facebook pages and Twitter accounts can be very revealing.
We had a person suing for major damages claiming a variety of injuries. Her Twitter account revealed that she was living a quite active life, in direct contradiction to her supposed ailments.
If was screening candidates, the Internet would be a negative indicator only (beer bong or Lingerie pics). Anyone with a big Internet footprint would not be hired because it tells me:
1) He/she is stupid (putting personal info on the Internet invites ID fraud)
2) He/she is self-absorbed
3) He/she is a time waster (those of us who WORK for a living don’t have time for all that crap — a few FReeps is about all we have time for)
Hire these idiots at your peril.
If you are hiring a(n)(insert name of favorite group here) Outreach Coordinator, social media or (more likely) software matters because you have a ton of candidates to sort through. If you are hiring a field welder, only the skill set matters, because if you don't make a decision soon, then one of your competitors will.
A little while back I changed jobs. I am on the upper end of the pay scale and got the full and through exam. The HR person did not like the fact that I did not have a twitter or Facebook account. This was told to my face at the board review.
My response shocked them. I told them that I don’t want people to know me, know of me, know where I live. I keep that information very restricted. When the HR lady asked if I had something to hide I told her yes. The very lives of my children and my wife.
You see, I have designed security systems and disaster recovery systems for some very large international banks. And some of those banks are located in places like Turkey, Jordan and Egypt. I do not want to expose my family to any potential threats.
The board passed my unanimously.
Either having an account or not having an account seems to be a form of double jeopardy that can cause problems either way. For now, I continue to err on the side of caution.
And, as Michele Rafter explains at the Second Act site, there are some interactive techniques that jobhunters should employ in order to increase their marketability. (I like the term presume, short for presentation resume.) The ideal presume could include an online interactive slide presentation (SlideRocket is the platform cited), an infographic (yikes), a video resume, a something still printed but on something unusual, with lots of eye-popping graphics.
Trust me: do NOT submit a "presume".

Works on every median strip I try it on.
A one-point primer on one of the flaws of this ‘great society’; class, experience, ethics have no value. ONLY SMOKE!
“Resumes, shmeszchumes, sleep your way to the top!” - Babawa Wawa
By the way, how does one delete one’s police mugshots from the Internet?