Over time, Facebook users grew more reluctant to share personal details
Information visible on 5,076 Facebook profiles that were part of the Carnegie Mellon University network, 2005–13. Information was coded as "visible" if it could be seen by another user on the Carnegie Mellon network who was not a friend. After declining for years, sharing rose sharply between 2009 and 2010. This reversal may have been partially unintentional, as it coincided with an update to Facebook's privacy settings that many users found confusing.
Note: blank rectangles denote missing data.
Source: adapted from Table 3 of Stutzman et al. (2012)