Collecting Facebook, LinkedIn profiles
The http://Attentive.ly CiviCRM integration automatically returns the social media accounts that match with over a hundred social media sites including Twitter, LinkedIn, Facebook, Google+, Klout, etc., as well as social listening on relevant recent posts to Twitter and Facebook. It does a lot more to help improve your organization's online engagement with top influencers (meaning those that have a high Klout score). The service is not free, and works best for organizations that have at least 25,000 - 50,000 contacts. See https://civicrm.org/extensions/attentively-integration.