We also sawa very interesting difference play out in users’ perceptions of privacy when it came to tagging and app engagement with friends. Even though both promote engagement through co-owned personal information being shared between and through friends, the privacy implications were perceived differently. For app engagement, individual privacy concern was not a significant factor. However, the effectiveness of Facebook’s privacy policy was an important
factor to Facebook users when associated with app engagement with friends. In this case, we believe that the lack of transparency of the information flow (Nissenbaum, 2004) reduced users’ privacy awareness of the responsibility shared by their friends to appropriately share their personal information. Instead, Facebook users seem to place this responsibility on Facebook even though Facebook apps are third-party modules independent of Facebook.Acrucial implication for SNS designers then becomes the level of control they give to third-party app developers when integrating with their SNS platforms. Users expect SNSs’ privacy policies to protect them when they engage with their friends through apps; therefore, failure to do so may reduce SNS users’ emotional attachment to the SNS site, even if a breach was caused by an SNS user’s friend or a third-party app developer.