Collaborative systems, such as Online Social Networks and the Internet of Things, enable users to share privacy sensitive content. Content in these systems is often co-owned by multiple users with different privacy expectations, leading to possible multiuser privacy conflicts. In order to resolve these conflicts, various agreement mechanisms have been designed and agents that could participate in such mechanisms have been proposed. However, research shows that users hesitate to use software tools for managing their privacy. To remedy this, we argue that users should be supported by trustworthy agents that adhere to the following criteria: (i) concealment of privacy preferences, such that only necessary information is shared with others, (ii) equity of treatment, such that different kinds of users are supported equally, (iii) collaboration of users, such that a group of users can support each other in agreement and (iv) explainability of actions, such that users know why certain information about them was shared to reach a decision. Accordingly, this paper proposes PACCART, an open-source agent that satisfies these criteria. Our experiments over simulations and user study indicate that PACCART increases user trust significantly.

翻译：协作系统（如在线社交网络和物联网）允许用户共享隐私敏感内容。这些系统中的内容常由多名具有不同隐私预期的用户共同拥有，可能导致多用户隐私冲突。为解决此类冲突，研究者设计了多种协议机制，并提出了可参与这些机制的智能体。然而，研究表明用户对使用隐私管理软件工具持犹豫态度。为此，我们认为用户应得到遵循以下标准的可信智能体支持：（i）隐藏隐私偏好，仅向他人共享必要信息；（ii）公平对待，同等支持不同类型用户；（iii）用户协作，支持用户群体在协议中相互协作；（iv）行为可解释性，使用户了解为何共享其特定信息以达成决策。据此，本文提出PACCART——一个满足上述标准的开源智能体。基于模拟实验和用户研究的结果表明，PACCART显著提升了用户信任度。