With advances in generative AI, there is increasing work towards creating autonomous agents that can manage daily tasks by operating user interfaces (UIs). While prior research has studied the mechanics of how AI agents might navigate UIs and understand UI structure, the effects of agents and their autonomous actions—particularly those that may be risky or irreversible—remain under-explored. In this work, we investigate the real-world impacts and consequences of mobile UI actions taken by AI agents. We began by developing a taxonomy of the impacts of mobile UI actions through a series of…