User Perception and Expectations on Deleting Instant Messages -or- "What Happens If I Press This Button?"

Theodor Schnitzler, Christine Utz, Florian Farke, Christina Pöpper, Markus Dürmuth

European Workshop on Usable Security (EuroUSEC) 2018, London, England, 23 April 2018


Contemporary mobile messaging provides rich text and multimedia functionality leaving detailed trails of sensitive user information that can span long periods of time. Allowing users to manage the privacy implications both on the sender and the receiver side can help to increase confidence in the use of communication applications. Recently, in October 2017, one of the mobile messengers with the largest user base, WhatsApp, has introduced a feature to delete past messages from communication, both from the sender's and the receiver's logs.

In this paper, we report on a study with 125 participants conducted in a between-subjects design. We explore the actual demand for deleting mobile messages, and we investigate how well users comprehend this functionality as implemented in popular messaging applications. We found statistically significant differences in users' understanding of message deletion between our three test conditions, comprising WhatsApp, Facebook Messenger, and Skype. 80% of participants in the WhatsApp condition could correctly assess the effects of deleting messages, compared to only 49% in the Skype condition.

Our findings indicate that users demand a message deleting functionality and that they can more precisely estimate the capabilities of a deletion function when its effects are transparently explained in the application's user interface.

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tags: Digital Forgetting, Messaging, Mobile Systems, privacy, Usability