In this age of social media, it almost seems as though if you don’t have a facebook, linked-in, or twitter you don’t exist.  While these social media outlets are a fun way to interact with friends, thinking that your personal facebook page is off-limits to companies while you are going through a job interview process is simply naive.  The truth is, that is one of the first things you will be judged by. 
While I am not suggesting you delete your social media accounts, there are some ways to avoid losing the job of a lifetime based on a poor professional image on those social media websites.  If you use your facebook or twitter purely for professional purposes you are probably safe to have that account public.  It may also become a positive aspect to work for you if you publicly display your abilities, solid communication skills, or even your creativity.  However, if you don’t want to keep your social media accounts strictly professional, I would recommend taking every privacy measure you can to keep your personal life to yourself.  No hiring manager wants to see pictures from your birthday party or your tailgating endeavors. 
 
I would highly recommend reading this article to further learn about specific aspects of social media profiles that could cost you the job interview:
https://mashable.com/2011/10/23/how-recruiters-use-social-networks-to-screen-candidates-infographic/