  Social platforms are heavily used by individuals to share their thoughts and
personal information. However, due to regret over time about posting
inappropriate social content, embarrassment, or even life or relationship
changes, some past posts might also pose serious privacy concerns for them. To
cope with these privacy concerns, social platforms offer deletion mechanisms
that allow users to remove their contents. Quite naturally, these deletion
mechanisms are really useful for removing past posts as and when needed.
However, these same mechanisms also leave the users potentially vulnerable to
attacks by adversaries who specifically seek the users' damaging content and
exploit the act of deletion as a strong signal for identifying such content.
Unfortunately, today user experiences and contextual expectations regarding
such attacks on deletion privacy and deletion privacy in general are not well
understood.
  To that end, in this paper, we conduct a user survey-based exploration
involving 191 participants to unpack their prior deletion experiences, their
expectations of deletion privacy, and how effective they find the current
deletion mechanisms. We find that more than 80% of the users have deleted at
least a social media post, and users self-reported that, on average, around 35%
of their deletions happened after a week of posting. While the participants
identified the irrelevancy (due to time passing) as the main reason for content
removal, most of them believed 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., the government) than individuals from their
social circle. Finally, the participants felt that popular deletion mechanisms
are not very effective in protecting the privacy of those deletions.
