This paper reports on a study exploring how two groups of individuals, legally blind (n=36) and sighted ones (n=36), react to aural telephone scam warnings in naturalistic settings. As spoofing a CallerID is trivial, communicating the context of an incoming call instead offers a better possibility to warn a receiver about a potential scam. Usually, such warnings are visual in nature and fail to cater to users with visual disabilities. To address this exclusion, we developed an aural variant of telephone scam warnings and tested them in three conditions: baseline (no warning), short warning, and contextual warning that preceded the scam's content. We tested the two most common scam scenarios: fraud (interest rate reduction) and identity theft (social security number) by cold-calling participants and recording their action, and debriefing and obtaining consent afterward. Only two participants "pressed one" as the scam demanded, both from the legally blind group that heard the contextual warning for the social security scenario. Upon close inspection, we learned that one of them did so because of accessibility issues with their screen reader and the other did so intentionally because the warning convinced them to waste the scammer's time, so they don't scam vulnerable people. Both the legally blind and the sighted participants found the contextual warnings as powerful usable security cues that, together with STIR/SHAKEN indicators like "Scam Likely", would provide robust protection against any type of scam. We also discussed the potential privacy implications of the contextual warnings and collected recommendations for usably accessible implementation.

翻译：本文报告了一项研究，探讨了两组人群——法定盲人（n=36）与视力正常者（n=36）——在自然情境下对电话诈骗语音警告的反应。由于伪造来电显示轻而易举，向来电接收者传达来电背景信息，而非单纯依赖号码，为警示潜在诈骗提供了更有效的可能。通常，此类警告本质上是视觉性的，无法满足视障用户的需求。为解决这一排斥问题，我们开发了一种电话诈骗的语音警告变体，并在三种条件下进行了测试：基线（无警告）、简短警告以及在诈骗内容之前播放的背景信息警告。我们通过电话陌生拜访参与者，测试了两种最常见的诈骗场景：金融诈骗（利率下调）和身份盗窃（社会安全号码），记录了他们的行为，并在事后进行情况说明并获取同意。仅有两位参与者按照诈骗要求“按了1键”，两人均来自法定盲人组，且听到的是社会安全号码场景的背景信息警告。经仔细调查，我们发现其中一人这样做是因为其屏幕阅读器存在可访问性问题，另一人则是故意为之，因为警告说服他们去浪费诈骗者的时间，以防止其诈骗弱势群体。法定盲人和视力正常的参与者均认为，背景信息警告是强大且可用的安全提示，若与“疑似诈骗”等STIR/SHAKEN标识结合使用，将为抵御任何类型的诈骗提供强有力的保护。我们还讨论了背景信息警告潜在的隐私影响，并收集了关于如何实现可用且可访问的实施方案的建议。