In recent years, Online Social Networks (OSN) have become popular content-sharing environments. With the emergence of smartphones with high-quality cameras, people like to share photos of their life moments on OSNs. The photos, however, often contain private information that people do not intend to share with others (e.g., their sensitive relationship). Solely relying on OSN users to manually process photos to protect their relationship can be tedious and error-prone. Therefore, we designed a system to automatically discover sensitive relations in a photo to be shared online and preserve the relations by face blocking techniques. We first used the Decision Tree model to learn sensitive relations from the photos labeled private or public by OSN users. Then we defined a face blocking problem and developed a linear programming model to optimize the tradeoff between preserving relationship privacy and maintaining the photo utility. In this paper, we generated synthetic data and used it to evaluate our system performance in terms of privacy protection and photo utility loss.
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"My face, my rules": Enabling Personalized Protection Against Unacceptable Face Editing
Today, face editing is widely used to refine/alter photos in both professional and recreational settings. Yet it is also used to modify (and repost) existing online photos for cyberbullying. Our work considers an important open question: 'How can we support the collaborative use of face editing on social platforms while protecting against unacceptable edits and reposts by others?' This is challenging because, as our user study shows, users vary widely in their definition of what edits are (un)acceptable. Any global filter policy deployed by social platforms is unlikely to address the needs of all users, but hinders social interactions enabled by photo editing. Instead, we argue that face edit protection policies should be implemented by social platforms based on individual user preferences. When posting an original photo online, a user can choose to specify the types of face edits (dis)allowed on the photo. Social platforms use these per-photo edit policies to moderate future photo uploads, i.e., edited photos containing modifications that violate the original photo's policy are either blocked or shelved for user approval. Realizing this personalized protection, however, faces two immediate challenges: (1) how to accurately recognize specific modifications, if any, contained in a photo; and (2) how to associate an edited photo with its original photo (and thus the edit policy). We show that these challenges can be addressed by combining highly efficient hashing based image search and scalable semantic image comparison, and build a prototype protector (Alethia) covering nine edit types. Evaluations using IRB-approved user studies and data-driven experiments (on 839K face photos) show that Alethia accurately recognizes edited photos that violate user policies and induces a feeling of protection to study participants. This demonstrates the initial feasibility of personalized face edit protection. We also discuss current limitations and future directions to push the concept forward.
more » « less- NSF-PAR ID:
- 10495505
- Publisher / Repository:
- Proceedings on Privacy Enhancing Technologies
- Date Published:
- Journal Name:
- Proceedings on Privacy Enhancing Technologies
- Volume:
- 2023
- Issue:
- 3
- ISSN:
- 2299-0984
- Page Range / eLocation ID:
- 252 to 267
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Photo sharing has become increasingly easy with the rise of social media. Social networking sites (SNSs), such as Instagram and Facebook, are well known for their image-sharing capabilities. However, this brings the concern of photo privacy, such as who may see the images of a user who is included in a post. Photo privacy settings offer detailed and more secure ways to share a user’s photos, however, this would require SNS users to understand these settings. To better grasp users’ understanding of photo privacy settings, we conducted a structured interview with Instagram users. We found that users were aware of the majority of the privacy settings asked about and that they accurately perceived their photo privacy safety based on their knowledge of photo privacy settings.
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We investigate the effects of perspective taking, privacy cues, and portrayal of photo subjects (i.e., photo valence) on decisions to share photos of people via social media. In an online experiment we queried 379 participants about 98 photos (that were previously rated for photo valence) in three conditions: (1) Baseline: participants judged their likelihood of sharing each photo; (2) Perspective-taking: participants judged their likelihood of sharing each photo when cued to imagine they are the person in the photo; and (3) Privacy: participants judged their likelihood to share after being cued to consider the privacy of the person in the photo. While participants across conditions indicated a lower likelihood of sharing photos that portrayed people negatively, they – surprisingly – reported a higher likelihood of sharing photos when primed to consider the privacy of the person in the photo. Frequent photo sharers on real-world social media platforms and people without strong personal privacy preferences were especially likely to want to share photos in the experiment, regardless of how the photo portrayed the subject. A follow-up study with 100 participants explaining their responses revealed that the Privacy condition led to a lack of concern with others’ privacy. These findings suggest that developing interventions for reducing photo sharing and protecting the privacy of others is a multivariate problem in which seemingly obvious solutions can sometimes go awry.more » « less
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‘Interdependent’ privacy violations occur when users share private photos and information about other people in social media without permission. This research investigated user characteristics associated with interdependent privacy perceptions, by asking social media users to rate photo-based memes depicting strangers on the degree to which they were too private to share. Users also completed questionnaires measuring social media usage and personality. Separate groups rated the memes on shareability, valence, and entertainment value. Users were less likely to share memes that were rated as private, except when the meme was entertaining or when users exhibited dark triad characteristics. Users with dark triad characteristics demonstrated a heightened awareness of interdependent privacy and increased sharing of others’ photos. A model is introduced that highlights user types and characteristics that correspond to different privacy preferences: privacy preservers, ignorers, and violators. We discuss how interventions to support interdependent privacy must effectively influence diverse users.more » « less
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null (Ed.)We investigate how people’s ‘humor style’ relates to their online photo-sharing behaviors and reactions to ‘privacy primes’. In an online experiment, we queried 437 participants about their humor style, likelihood to share photo-memes, and history of sharing others’ photos. In two treatment conditions, participants were either primed to imagine themselves as the photo-subjects or to consider the photo-subjects’ privacy before sharing memes. We found that participants who frequently use aggressive and self-deprecating humor were more likely to violate others’ privacy by sharing photos. We also replicated the interventions’ paradoxical effects – increasing sharing likelihood – as reported in earlier work and identified the subgroups that demonstrated this behavior through interaction analyses. When primed to consider the subjects’ privacy, only humor deniers (participants who use humor infrequently) demonstrated increased sharing. In contrast, when imagining themselves as the photo-subjects, humor deniers, unlike other participants, did not increase the sharing of photos.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.56553/POPETS-2023-0080
