"Since LinkedIn doesn’t require you to share the same types of personal information as you do on Facebook, the service’s privacy settings appear to be much more straightforward than its less business-oriented competitor. But if you leave the default settings in place, you might be surprised to know what information you make public on LinkedIn.
How private you decide to make your LinkedIn information will affect the inquiries you receive for job opportunities as well as, in some cases, the amount of information you’re able to find about others. To access the privacy settings, simply log into LinkedIn and click on the Account & Settings tab in the upper right hand corner of your homepage." – Content courtesy of LinkedIn Privacy Settings: What You Need to Know