70 percent of Facebook members are “somewhat” or “very concerned” about their privacy. Facebook’s location-based check-in service, “Places,” in August 2010, was met with concerns about its people tagging feature. Facebook doesn’t sell your information to advertisers and says it won’t in the future. If you participate in social ads, your friends might see information about you that relates to the ads they’re seeing. You might occasionally notice ads in the margins of your Facebook profile and elsewhere on the site.”]
Source: https://www.csoonline.com/article/2127003/facebook-privacy–4-valuable-yet-hard-to-find-settings.html