An IoT device in a Faraday cage is about as good as a paperweight. Yet, the inherent openness of wireless systems leaves IoT devices exposed to vulnerabilities. These vulnerabilities are unavoidable precisely because inputs into radio receivers cannot be sealed off and wireless links cannot be completely isolated. Left unaddressed, these spectrum vulnerabilities can be exploited by malicious actors or be the source of non-malicious harmful interference, both of which can have high social and economic costs. Notwithstanding these vulnerabilities, wireless devices have become increasingly prevalent, and our reliance on radios is only expected to increase. This is unsurprising considering that connected devices have become indispensable to public safety and national security communications, business and critical infrastructure operations, navigation, socializing, and entertainment. Stakeholders and policymakers have only just begun to understand how the prevalence of connected devices and their vulnerabilities results in a high number of actual and potential security risks. Consequently, they have struggled to identify and understand those risks, let alone develop solutions to address them. If vulnerabilities cannot be identified, they cannot be prioritized, and if they cannot be prioritized, they will not be sufficiently resourced. In March 2019, I was invited to attend and report on a roundtable discussion convened by Silicon Flatirons that brought together experts from government, academia, and industry to discuss spectrum vulnerabilities. This column, which will be presented in two parts, captures some of the discussion. Part I will focus on the systematic and technological challenges to identifying and understanding spectrum vulnerabilities. Part II, which will appear in the next issue of IEEE Internet of Things Magazine, will focus on recommendations to address those challenges. The ideas and conclusions herein are attributable to the participants, who engaged in the conversation under the Chatham House Rule.