"My Friend Wanted to Talk About It and I Didn't": Understanding Perceptions of Deletion Privacy in Social Platforms.

There is a growing concern and awareness about the right-to-be-forgotten issues among regulators as well as users all over the world. To cope with these privacy concerns, social platforms offer deletion mechanisms that give the users the opportunity to remove their contents and in some cases the platforms remove them automatically. However, this leaves the users vulnerable to attacks by adversaries who specifically seek the damaging content of the users and exploit the act of deletion as a strong signal for it. In this paper, we conduct a user study on 191 participants to study their prior deletion experiences, their expectations of deletion privacy, and how effective do they find the current deletion mechanisms. We find that more than 80\% of the users have deleted at least a social media post and 35\% of the deletions happened after a week of posting. While the participants identified the irrelevancy of the content due to time passing as the main reason for removing their contents, a majority of the participant believe that deletions indicate that the deleted content includes some damaging information to the owner. Importantly, the participants are significantly more concerned about their deletions being noticed by large-scale data collectors (e.g., a third-party data collecting company or the government) than any other individual from their social circle. Further, a third of the participants think that they can be attacked by these large-scale data collectors. Finally, the participants find the current deletion mechanisms to be inadequate in protecting the privacy of their deletions and provide guidelines for the future of deletion mechanisms.