Across the globe, banks are flagging accounts with indicia indicating their owners may be “US Persons,” clearing the way for the United States to enforce citizenship-based taxation extraterritorially for the first time in history. For individuals who permanently reside outside of the United States, this is a “where there’s smoke” method of establishing tax jurisdiction because none of the indicia are themselves incontrovertible evidence of one’s status as a citizen and therefore a US Person for tax purposes. The indicia method guarantees that certain individuals will be presumed to be citizens and subjected to repercussions regardless of their actual legal status as such, while others will be overlooked even if they are in fact citizens. Establishing a tax jurisdiction in this manner is arbitrary and capricious, with significant practical and normative consequences. Moreover, it violates one of the most fundamental and universally- acknowledged tenets of taxpayer rights, namely, the right to be informed about what the law requires. Because of the extraordinary demands that the United States attaches to citizenship, indicia-searching and self-verification of nonresidents violate principles of both international law and human rights. Both should be universally rejected as an invalid exercise of state power.