We analyse Stack Overflow (SO) to understand challenges and confusions developers face while dealing with privacy-related topics. We apply topic modelling techniques to 1,733 privacyrelated questions to identify topics and then qualitatively analyse a random sample of 315 privacy-related questions. Identified topics include privacy policies, privacy concerns, access control, and version changes. Results show that developers do ask SO for support on privacy-related issues. We also find that platforms such as Apple and Google are defining privacy requirements for developers by specifying what "sensitive" information is and what types of information developers need to communicate to users (e.g. privacy policies). We also examine the accepted answers in our sample and find that 28% of them link to official documentation and more than half are answered by SO users without references to any external resources.

Software developers are key players in the security ecosystem as they produce code that runs on millions of devices. Yet we continue to see insecure code being developed and deployed on a regular basis despite the existence of support infrastructures, tools, and research into common errors. This work provides a systematised overview of the relatively new field of Developer-Centred Security which aims to understand the context in which developers produce security-relevant code as well as provide tools and processes that that better support both developers and secure code production. We report here on a systematic literature review of 49 publications on security studies with software developer participants. We provide an overview of both the types of methodologies currently being used as well as the current research in the area. Finally, we also provide recommendations for future work in Developer-Centred Security.

Software development teams are responsible for making and implementing software design decisions that directly impact end-user privacy, a challenging task to do well. Privacy Champions-people who strongly care about advocating privacy-play a useful role in supporting privacy-respecting development cultures. To understand their motivations, challenges, and strategies for protecting end-user privacy, we conducted 12 interviews with Privacy Champions in software development teams. We fnd that common barriers to implementing privacy in software design include: negative privacy culture, internal prioritisation tensions, limited tool support, unclear evaluation metrics, and technical complexity. To promote privacy, Privacy Champions regularly use informal discussions, management support, communication among stakeholders, and documentation and guidelines. They perceive code reviews and practical training as more instructive than general privacy awareness and on-boarding training. Our study is a frst step towards understanding how Privacy Champions work to improve their organisation's privacy approaches and improve the privacy of enduser products. CCS CONCEPTS• Human-centered computing → Empirical studies in collaborative and social computing; • Security and privacy → Usability in security and privacy; • Social and professional topics → Software management.

Advertising networks enable developers to create revenue, but using them potentially impacts user privacy and requires developers to make legal decisions. To understand what privacy information ad networks give developers, we did a walkthrough of four popular ad network guidance pages with a senior Android developer by looking at the privacy-related information presented to developers. We found that information is focused on complying with legal regulations, and puts the responsibility for such decisions on the developer. Also, sample code and settings often have privacyunfriendly defaults laced with dark patterns to nudge developers' decisions towards privacy-unfriendly options such as sharing sensitive data to increase revenue. We conclude by discussing future research around empowering developers and minimising the negative impacts of dark patterns. CCS CONCEPTS• Security and privacy → Human and societal aspects of security and privacy; • Software and its engineering → Software creation and management; • Information systems → Online advertising.

Mobile apps enable ad networks to collect and track users. App developers are given “configurations” on these platforms to limit data collection and adhere to privacy regulations; however, the prevalence of apps that violate privacy regulations because of third parties, including ad networks, begs the question of how developers work through these configurations and how easy they are to utilize. We study privacy regulations-related interfaces on three widely used ad networks using two empirical studies, a systematic review and think-aloud sessions with eleven developers, to shed light on how ad networks present privacy regulations and how usable the provided configurations are for developers. We find that information about privacy regulations is scattered in several pages, buried under multiple layers, and uses terms and language developers do not understand. While ad networks put the burden of complying with the regulations on developers, our participants, on the other hand, see ad networks responsible for ensuring compliance with regulations. To assist developers in building privacy regulations-compliant apps, we suggest dedicating a section to privacy, offering easily accessible configurations (both in graphical and code level), building testing systems for privacy regulations, and creating multimedia materials such as videos to promote privacy values in the ad networks’ documentation.