Extensive research has focused on community-based moderation involving selected or volunteer moderators. The "votekick" system represents a democratized approach allowing all users to participate in moderation. Despite its widespread use in online gaming and social VR platforms, votekicking remains underexplored. This research studies how users use and perceive votekicking in VRChat, a leading social VR platform. Through thematic analysis of discussions from the Reddit community r/VRChat, our findings reveal that votekicking serves to cope with misconduct and enforce group-specific rules, but it also perpetuates toxicity such as materializing community-level biases. While praised for its immediacy and clear messaging against unacceptable behavior, votekicking's effectiveness is hindered by its reactive nature, consensus challenges, and decision-making complexities. This research contributes to broader discussions on the limitations and advantages of direct community involvement in moderation and suggests practical design improvements to address the challenges associated with votekicking.

Algorithms have played a central role in personalized recommendations on social media. However, they also present significant obstacles for content creators trying to predict and manage their audience reach. This issue is particularly challenging for marginalized groups seeking to maintain safe spaces. Our study explores how women on Xiaohongshu (rednote), a recommendation-driven social platform, proactively re-appropriate hashtags (e.g., #Baby Supplemental Food) by using them in posts unrelated to their literal meaning. The hashtags were strategically chosen from topics that would be uninteresting to the male audience they wanted to block. Through a mixed-methods approach, we analyzed the practice of hashtag re-appropriation based on 5,800 collected posts and interviewed 24 active users from diverse backgrounds to uncover users' motivations and reactions towards the re-appropriation. This practice highlights how users can reclaim agency over content distribution on recommendation-driven platforms, offering insights into self-governance within algorithmic-centered power structures.

This paper proposes a fault-tolerant control (FTC) scheme with non-sinusoidal current patterns for single-phase open-phase fault (OPF) and two-phase OPFs in dual three-phase permanent magnet synchronous motor (DTP-PMSM) drive systems. First, current references are reconstructed through the injection of harmonic currents. Different from the schemes with sinusoidal current patterns, the proposed scheme further releases the degree of control freedom and expands the optimization solution space. Second, global optimization of the current references is achieved by utilizing an intelligent algorithm. For single-phase OPF, both minimum-copper-loss (ML) and maximum-torque (MT) fault-tolerant modes are investigated to accommodate various operating conditions. Finally, four fault categories of two-phase OPFs are separately discussed and optimized. Theoretical and experimental results demonstrate that the proposed FTC scheme enhances fault-tolerant performance, providing a robust solution for OPFs.

Online communities are susceptible to racist attacks, even when community policies explicitly prohibit racism. Drawing on the concept of symbolic boundary, we explored how community members sustained their communities against the perpetuation of racist logics and practices on Reddit. We drew on trace ethnography to analyze conversations about crime in two city subreddits (i.e., r/baltimore and r/chicago). The findings illustrate that the fragility of community boundaries was contributed by race baiting posts, covert racism, and racist brigading. At the same time, our research highlights that moderation efforts maintained and established institutional, cultural, and geographical boundaries to combat racist attacks. We discuss boundary as a design technique for building safe spaces for community members. Content warning: This work contains racist quotes that can upset or harm some readers.

Abstract Social media have long been studied from platform‐centric perspectives, which entail sampling messages based on criteria such as keywords and specific accounts. In contrast, user‐centric approaches attempt to reconstruct the personalized information environments users create for themselves. Most user‐centric studies analyze what users have accessed directly through browsers (e.g., through clicks) rather than what they may have seen in their social media feeds. This study introduces a data collection system of our own design called PIEGraph that links survey data with posts collected from participants' personalized X (formerly known as Twitter) timelines. Thus, in contrast with previous research, our data include much more than what users decide to click on. We measure the total amount of data in our participants' respective feeds and conduct descriptive and inferential analyses of three other quantities of interest: political content, ideological skew, and fact quality ratings. Our results are relevant to ongoing debates about digital echo chambers, misinformation, and conspiracy theories; and our general methodological approach could be applied to social media beyond X/Twitter contingent on data availability.

Contemporary feminists utilize social media for activism, while backlashes come along. The gender-related discourses are often diminished when addressing public events regarding sexism and gender inequality on social media platforms. The dichotomous debate around the Tangshan beating incident in China epitomized how criminal interpretations of gender-related violence became a backlash against feminist expressions. By analyzing posts on Weibo using mixed methods, we describe the emerging discursive patterns around crime and gender, uncovering the gender-blind sexism that refutes feminist discourses on the social platform. We also highlight the critical hurdles facing grassroots feminist activism in Chinese cyberspace and propose implications for the design and research related to digital feminist activism.

Volunteer moderators serve as gatekeepers for problematic content, such as racism and other forms of hate speech, on digital platforms. Prior studies have reported volunteer moderators' diverse roles in different governance models, highlighting the tensions between moderators and other stakeholders (e.g., administrative teams and users). Building upon prior research, this paper focuses on how volunteer moderators moderate racist content and how a platform's governance influences these practices. To understand how moderators deal with racist content, we conducted in-depth interviews with 13 moderators from city subreddits on Reddit. We found that moderators heavily relied on AutoMod to regulate racist content and racist user accounts. However, content that was crafted through covert racism and "color-blind'' racial frames was not addressed well. We attributed these challenges in moderating racist content to (1) moderators' concerns of power corruption, (2) arbitrary moderator team structures, and (3) evolving forms of covert racism. Our results demonstrate that decentralized governance on Reddit could not support local efforts to regulate color-blind racism. Finally, we discuss the conceptual and practical ways to disrupt color-blind moderation.

Due to the limitations imposed by the COVID-19 pandemic, customers have shifted their shopping patterns from offline to online. Livestream shopping has become popular as one of the online shopping media. However, various streamers’ malicious selling behaviors have been reported. In this research, we sought to explore streamers’ malicious selling strategies and understand how viewers perceive these strategies. First, we recorded 40 livestream shopping sessions from two popular livestream platforms in China—Taobao, and TikTok. We identified 16 malicious selling strategies that were used to deceive, coerce, or manipulate viewers and found that platform designs enhanced nine of the malicious selling strategies. Second, through an interview study with 13 viewers, we report three challenges of overcoming malicious selling in relation to imbalanced power between viewers, streamers, and the platforms. We conclude by discussing the policy and design implications of countering malicious selling.

With the emergence of Information and Communication Technologies (ICTs), people are being exposed to an increased volume of crime-related information, which induces fear. While the fear of crime has been explored around people's experiences with crime, little is known about how people frame their conversations about crime online. In this study, we explore how citizens talk about crime on Reddit. By collecting crime conversations from the subreddit r/baltimore, we find that, on the surface, redditors discuss topics such as comparing crime rates in Baltimore with other cities in an effort to destigmatize the depictions of Baltimore as a city rife with crime. On a deeper level, we find that through their conversations about crime, redditors are engaging in discourse frames that both re-enforce and fight against platformed racism. On the one hand, some redditors perpetuate racially coded language that is rife with anti-Black stereotypes, framing their conversations using old and new racism to cover their racism and discrimination against Black people. On the other hand, others push back against platformed racism by drawing attention to individual racism and systemic racism, and situating crime in root, societal causes. We then discuss how platformed racism operates in online conversations, and develop the concepts of weaponized identity and digital gentrification, which we argue are ways in which people, through their engagements in digital platforms, continue to perpetuate white hegemonic power structures in society. Finally, we discuss implications for how to design to support the fight against platformed racism in sociotechnical systems like Reddit. As a content note and warning, this paper discusses racist content which may be upsetting or harmful to some readers.

A large body of literature is dedicated to understanding people's check-in behavior when they use location sharing services to pair their location with a venue, e.g., a restaurant, a park, etc. Check-in behavior in higher education settings, e.g., where students and instructors have academic purposes for check-ins, is under-studied. In this work, we explore how university students apply two different mechanisms, i.e., automatic and manual location-sharing services, to conduct check-ins for an academic purpose (i.e., students sharing their class attendance with their instructor). More specifically, a Bluetooth Low Energy beacon-based technology is applied to enable automatic class check-ins. We conducted two field trials with a total of 141 university students. Our findings showed that several social, technological, and psychological factors impacted the use of auto and manual check-ins. Feedback from the student participants suggested that future higher education check-in systems may need to consider the integration of check-ins for a variety of purposes.

Danmaku is a new video comment feature that is gaining popularity. Unlike typical forum comments that are displayed with user names below videos, danmaku comments are overlaid on the screen of videos without showing users' information. Prior work studied forum comments and danmaku separately, and little work compared how these two features were used. We collected 38,399 danmaku comments and 16,414 forum comments posted in 2017 on 30 popular videos on Bilibili.com. We examined the usage of these two features in terms of user participation, language used, and ways of sharing knowledge. We found that more users posted danmaku comments, and they also posted these more frequently than forum comments. Even though, in total, more negative language was used in danmaku comments than in forum comments, active users appeared to post more positive comments in danmaku. There was no such correlation in forum comments. It is interesting to find that danmaku and forum comments enabled knowledge sharing in a complementary manner, where danmaku comments involved more explicit knowledge sharing and forum comments exhibited more tacit knowledge sharing. We discuss design implications to promote social interactions for online video systems.